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ANNEX X-2: TECHNICAL GLOSSARY

BSC Section X-2: Technical Glossary V51.0

Effective From Date:30/06/2022

Status:SUPERSEDED

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ANNEX X-2: TECHNICAL GLOSSARY

SUMMARY PAGE

Modification Proposal	Decision Date	Implementation Date	Version
P433 Self Governance	13/01/22	30/06/22	51.0
P375	24/02/21	30/06/22	51.0
P418	03/02/21	01/04/21	50.0
P383	28/02/20	01/04/21	50.0
P408 Self-Governance	09/07/20	02/02/21	49.0
P388 Self-Governance	08/08/19	01/04/20	48.0
P354	18/06/18	01/04/20	48.0
P394	12/12/19	27/02/20	47.0
P386 Self-Governance	13/06/19	07/11/19	46.0
P367 Self-Governance	14/06/18	27/06/19	45.0
P369	24/09/18	29/03/19	44.0
P344	24/08/18	28/02/19	43.0
P373 (Nullification of P297)	22/02/19	27/02/19	43.0
P297 (Nullified by P373)	28/04/14	01/11/18	43.0
P350	24/03/17	01/04/18	42.0
P357	13/12/17	22/02/18	41.0
P321 Self Governance	08/10/15	29/06/17	40.0
P347	19/01/17	01/04/17	39.0
P339 Self-Governance	08/12/16	01/04/17	39.0
P346 Self-Governance	10/11/16	01/04/17	39.0
P326 Self-Governance Alternative	14/04/16	23/02/17	38.0
P315 Alternative	20/10/15	30/06/16	37.0
P328	12/11/15	16/11/15	36.0
P305	02/04/15	05/11/15	35.0
P300	15/10/14	05/11/15	35.0
P276	20/07/12	31/03/14	34.0
P273 Self-Governance	23/02/12	23/02/12	33.0
P253	18/11/10	03/11/11	32.0
P243	20/01/10	04/11/10	31.0
P261	02/08/10	09/08/10	30.0
P239	21/09/09	05/11/09	29.0
P232	25/06/09	05/11/09	29.0
P217	18/10/08	05/11/09	29.0
P233	19/05/09	25/06/09	28.0
P215	23/04/08	25/06/09	28.0
P216	24/04/08	20/04/09	27.0
P225	07/08/08	06/11/08	26.0
P220	02/04/08	06/11/08	26.0
P219	02/04/08	06/11/08	26.0
P208	16/01/07	22/02/07	25.0
P194	23/02/06	02/11/06	24.0
P176	10/05/05	03/11/05	23.0
P172	29/04/05	06/05/05	22.0
ADN003	11/03/05	01/04/05	21.0
ORD002	01/04/05	01/04/05	21.0
P179	09/02/05	23/02/05	20.0
P124	18/05/04	01/12/04	19.0
P98	18/08/03	08/11/04	18.0
P131	05/04/04	03/11/04	17.0
P160	30/07/04	13/08/04	16.0
P125	08/08/03	01/05/04	15.0 Removed by P165
P165	14/04/04	28/04/04	15.0 Removed P125
P130	29/08/03	20/01/04	15.0
P81	17/12/02	28/09/03	14.0
P62	12/08/02	01/08/03	13.0
P78	09/09/02	11/03/03	12.0
P71	22/11/02	11/03/03	12.0
P101	02/01/03	23/01/03	11.0
P68	24/07/02	01/11/02	10.0
P86	23/09/02	30/09/02	9.0
P33	07/12/01	30/09/02	9.0
P2	16/10/01	30/09/02	9.0
P12	10/05/02	02/07/02	8.0
P46	14/05/02	22/05/02	7.0
P37	10/05/02	20/05/02	6.0
P22	07/12/01	01/04/02	5.0
P67	01/03/02	08/03/02	4.0
P18	22/08/01	25/09/01	3.0
P8	24/09/01	25/09/01	3.0
P10	14/05/01	11/05/01	2.0

Section X-2

Version 51.0

Effective Date: 30 June 2022

ANNEX X-2: TECHNICAL GLOSSARY

1. GENERAL

1.1 Introduction

1.1.1 This Annex to Section X sets out:

(a) technical definitions and acronyms applicable in the Code other than in relation to Section S;

(b) technical definitions and acronyms applicable only in relation to Section S;

(c) conventions applicable to the Code, including timing conventions, the use of superscripts/subscripts with variables, summations and mathematical operators; and

(d) the method of interpolation of variables.

1.2 Use of Mathematical Operators

1.2.1 The mathematical operators and conventions employed in the formulae and other algebraic expressions contained in the Code shall be construed in accordance with the following:

(a) the symbol * requires multiplication to be effected;

(b) in respect of any data items, the symbol ∈ refers to belonging to or falling within. For example a∈p denotes those Energy Accounts 'a' that belong to Party ‘p’, and j∈D denotes those Settlement Periods ‘j’ falling within Settlement Day ‘D’;

(d) the convention |FUNC| refers to the absolute value of the expression ‘FUNC’, that is the positive value whether the value obtained is positive or negative;

(e) Where in the Code the minimum value ('min') of a set of numbers is to be selected, then for the avoidance of doubt, the value selected shall be the negative number in that set with the greatest magnitude, or in the absence of any such negative number, the positive number in that set with the lowest magnitude. Where in the Code the maximum value ('max') of a set of numbers is to be selected, then for the avoidance of doubt, the value selected shall be the positive number in that set with the greatest magnitude, or in the absence of any such positive number, the negative number in that set with the lowest magnitude.

2. TECHNICAL TERMS AND INTERPRETATION APPLYING EXCEPT IN RELATION TO SECTION S

2.1 Introduction

2.1.1 Unless the context otherwise requires the provisions of this paragraph 2 as to the use, interpretation or definition of terms, expressions, acronyms, and subscripts and summations shall apply in relation to the Code except in Section S.

2.2 Use of Subscripts and Other Expressions

2.2.1 The subscripts and superscripts employed in the formulae and other algebraic expressions contained in the Code shall bear the respective meanings set out in Table X-1.

2.3 Glossary of Terms

2.3.1 Unless the context otherwise requires, and subject as provided in Table X-2, in the Code the words, expressions and acronyms set out in Table X-2 shall bear the respective meanings therein set out.

2.3.2 Table X-3 sets out for convenience the acronyms employed in the formulae and other algebraic expressions contained in the Code in alphabetical order of acronym name.

2.4 Sign Convention - Active Energy and Active Power

2.4.1 Subject to paragraph 2.4.2, the sign convention adopted in the Code is that all variables representing Active Energy or Active Power are:

(a) positive in any Settlement Period for which they represent Active Energy or Active Power delivered on to the Total System or (at any Systems Connection Points(s)) the Transmission System; and

(b) negative in any Settlement Period for which they represent Active Energy or Active Power off-taken from the Total System or (at any Systems Connection Points(s)) the Transmission System.

2.4.2 Paragraph 2.4.1 shall not apply in relation to:

(a) GSP Group Take;

(b) Offer Non-Delivery Volume, Period BM Unit Non-Delivery Offer Volume and any other variable representing Active Energy or Active Power derived by calculation undertaken pursuant to Section T,

which shall, for the avoidance of doubt, be positive, negative or zero as determined in accordance with the algebraic determination of such variable pursuant to the Code.

2.5 Sign Convention - Cashflows

2.5.1 The sign convention adopted in the Code in relation to amounts payable in respect of Trading Charges is explained in Section T1.2.3 and T1.2.4.

2.6 Use of Summations

2.6.1 Variables being summated are indicated by the use of the indices placed in preceding or following superscript or subscript position on the summation sign Σ, for example:

(a) Σ^c FUNC^c means the sum of the values of FUNC^c over all values of c.

(b) Σ_d FUNC_d means a sum of the values of FUNC_d over all values of d.

(d) Σ_d_∈_RFUNC_d means a sum of the values of FUNC_d over values of d belonging to the set R.

2.6.2 In some instances, where the summation over a particular variable is restricted to a subset of the possible values of such a variable as in paragraph 2.6.1(d), instead adopting of the convention in that paragraph, an equivalent result is achieved by limiting the summation in context, for example:

"Σ_dFUNC_d;

Where Σ_d represents a sum over all values of d belonging to the set R."

This is equivalent to Σ_d_∈_RFUNC_d.

2.6.3 In some instances, for convenience certain summations deviate from the above conventions and are further defined in context, for example:

"Σ_dFUNC_d;

Where Σ_d represents a sum over all values of d belonging to the set R."

Again, this is equivalent to Σ_d_∈_RFUNC_d.

3. TECHNICAL TERMS AND INTERPRETATION APPLYING IN RELATION TO SECTION S

3.1 Introduction

3.1.1 Unless the context otherwise requires the provisions of this paragraph 3 as to the use, interpretation or definition of terms, expressions, acronyms, and subscripts and summations shall apply only in relation to Section S.

3.2 Use of Subscripts and Other Expressions

3.2.1 The subscripts and superscripts employed in the formulae and other algebraic expressions contained in the Code shall bear the respective meanings set out in Table X-4.

3.3 Use of Summations

3.3.1 The summations employed in the formulae and other algebraic expressions contained in the Code shall bear the respective meanings set out in Table X-5.

3.4 Glossary of Terms

3.4.1 Unless the context otherwise requires, in the Code the words, expressions and acronyms set out in Table X-6 shall bear the respective meanings therein set out.

3.4.2 Table X-7 sets out for convenience the acronyms employed in the formulae and other algebraic expressions contained in the Code in alphabetical order of acronym name.

3.5 Consumption Component Classes

3.5.1 Table X-8 sets out the valid Consumption Component Classes as at the Code Effective Date.

3.5.2 The Panel may from time to time amend the list of valid Consumption Component Classes.

3.6 Linear Interpolation of Variables

3.6.1 In Section S of the Code, unless the context otherwise requires, whenever linear interpolation is referred to, the procedures set out in paragraphs 3.6.2 to 3.6.4 shall be followed.

3.6.2 Where the relationship between two variables, x and y, is defined only for a set of related pairs of spot values, (x₁, y₁), (x₂, y₂) ... (x_n, y_n), and where a value for y, y_i, is to be calculated by linear interpolation for a value of x, x_i, which is not a spot value contained in the set of related pairs, but which lies within the range of x spanned by the set of related pairs, the following formula shall be applied:

y_i = y₀ + ((y₁ - y₀) * (x_i - x₀)/(x₁ - x₀))

where x₀ refers to the value of x in that related pair in the set of related pairs in which x is less than x_i, and where the x of the related pair is the closest x to x_i;

x₁ refers to the value of x in that related pair in the set of related pairs in which x is greater than x_i, and where the x of the related pair is the closest x to x_i;

y₀ refers to the value of y related to x₀; and

y₁ refers to the value of y related to x₁.

3.6.3 Where x_i lies outside the range of x spanned by the set of related pairs, y_i shall be set equal to the value of y in that related pair in which the value of x is closest to x_i.

3.6.4 Where x_i is a value of x referred to in a related pair, y_i shall be set equal to the value of y contained in that related pair.

3.7 Sign Convention

With the exception of BM Unit Allocated Demand Volume, for the purposes of collecting and aggregating metered data as part of Supplier Volume Allocation pursuant to Section S, metered data, whether in respect of an Import (or aggregation of Imports) or an Export (or aggregation of Exports), will be held as the magnitude of the quantity which such metered data represents.

3.7.2 BM Unit Allocated Demand Volume shall be positive in any Settlement Period for which it represents Active Energy offtaken from the Total System and negative in any Settlement Period for which it represents Active Energy delivered to the Total System.

4 TIMING CONVENTIONS

4.1 Introduction

4.1.1 A number of variables within the Code are expressed as differing functions of time. This paragraph 4 defines the nomenclature used in such expressions.

4.1.2 Paragraphs 4.1 to 4.3 apply in relation to the Code including Section S but paragraphs 4.4 to 4.6 do not apply in relation to Section S.

4.2 Spot Time

4.2.1 Many input variables and calculated values are given for spot times within the Code.

4.2.2 Spot times are an instant in time, and have no duration.

4.3 Settlement Period Times

4.3.1 Settlement Period j starts at the spot time occurring at the beginning of the half hour and ends at the spot time occurring exactly 30 minutes later. The spot time at the beginning of one period therefore coincides with the spot time at the end of the previous period.

4.3.2 For the avoidance of doubt the first Settlement Period of a Settlement Day begins at the spot time 00:00 on the current Settlement Day (D), and ends at the spot time of 00:30 for the current Settlement Day D.

4.3A Quarter Hour Times

4.3A.1 Quarter Hours start at the spot time occurring at the beginning of the quarter hour and ends at the spot time occurring exactly 15 minutes later. The spot time at the beginning of one Quarter Hour period therefore coincides with the spot time at the end of the previous Quarter Hour period.

4.4 Point Variables

4.4.1 Where variables are determined in relation to spot times, they are termed ‘point’ variables. The values of point variables and their associated spot times are converted (as provided in Section T3.1) from data provided by the NETSO in a different format. There is a restriction on the resolution of the pre-conversion data, such that values of point variables to which this data is converted may only be for spot times expressed in a whole number of minutes.

4.4.2 Point variables are given the subscript 't', where 't' denotes the spot time to which the point variable applies. As point variables must be submitted in a whole number of minutes, there are 31 spot times for which point data may be submitted for any Settlement Period. Up to two point variables may be submitted for a single spot time. This is to accommodate step changes in the associated variable. As the first and last spot times for any Settlement Period coincide with the adjoining Settlement Periods, only one value may be submitted for these spot times. Thus for example for the period 12:30 – 13:00, only one value of point FPN may be submitted for spot times 12:30 and 13:00 (and up to 2 values for any other spot time which is a whole number of minutes and falls within the Settlement Period).

4.4.3 Whether or not step changes are expected depends upon the variable in question. For example, as FPN Data may normally be expected to comply with dynamic parameters, step changes (especially for generation) might not normally be expected. However, a Party’s view of their operating level may change significantly from one Gate Closure to the next, and step changes may be expected at the start of a Settlement Period.

4.4.4 Where two point values are submitted for the same spot time, the Point Variable Identification Number (f) is used to determine the sequence of the two values (as explained further in paragraph 4.5.4).

4.4.5 An example of a set of Point FPN data for Settlement Period (e.g. 12:30 – 13:00) is as follows:

Spot time, t	Point ^fFPN_ijt (MW)
12:30	200
12:37	235
12:57	245
13:00	245

4.4.6 The use of the subscript j is retained to represent the fact that the spot values are being submitted for spot times that fall within a particular Settlement Period.

4.5 Interpolation of Values of Point Variables Between Spot Times Supplied

4.5.1 For certain spot variables it may be necessary to evaluate values applicable to any spot time within a Settlement Period from the discrete point variables supplied. These are:

Name	Acronym	Units	Calculated from point variable:
Acceptance Volume	qA^k_ij(t)	MW	^fqA^k_ijt
Accepted Bid Volume	qAB^kn_ij(t)	MW	^fqAB^kn_ijt
Accepted Bid-Offer Volume	qABO^kn_ij(t)	MW	^fqABO^kn_ijt
Accepted Offer Volume	qAO^kn_ij(t)	MW	^fqAO^kn_ijt
Bid-Offer Volume	qBOⁿ_ij(t)	MW	^fqBOⁿ_ijt
FPN	FPN_ij(t)	MW	^fFPN_ijt
Deemed Standard Product Shape	qDSP^J_ij(t)	MW	^fDSP^J_ijt

4.5.2 Point variables for a particular parameter are normally used to calculate an associated function that is defined for all spot times in a Settlement Period, or in the time interval between such Point Variables. Such associated functions are expressed as a function of time F(t) and are calculated by linear interpolation from the point variables.

4.5.3 Whenever linear interpolation is referred to, the procedures set out in paragraphs 4.5.4 shall be followed.

4.5.4 Where for the purposes of the Code, a function of time F(t) is to be established by linear interpolation from a set of related pairs of spot values with point identification numbers and associated spot times t (each being a whole number of minutes) the following interpretation shall apply:

(a) For a spot time t_i which is not a spot value contained in the set of related pairs, but which lies within the range of t spanned by the set of related pairs, the following formula shall be applied:

F(t_i) = ^HF_t0 + (^LF_t1 – ^HF_t0)*(t_i – t₀)/(t₁–t₀)

where

t₀refers to the value of t in that related pair in the set of related pairs in which t is less than t_i, and where the t of the related pair is the closest t to t_i.

t₁refers to the value of t in that related pair in the set of related pairs in which t is greater than t_i, and where the t of the related pair is the closest t to t_i.

^HF_t0refers to the value of ^fF_t related to t₀ with the highest value of f; and

^LF_t1 refers to the value of ^fF_t related to t₁ with the lowest value of f.

(b) For a spot time t_i that is a value of t referred to in a related pair where a single value of ^fF_t exists, the value of F(t_i) shall be set to ^fF_ti contained in that related pair.

(c) For a spot time t_i that is a value of t referred to in a related pair where two values of ^fF_t exist, the value of F(t_i) shall (subject to 4.6.1(a)) and 4.6.1(b)) below) remain undefined for that time t_i.

4.6 Evaluation of Period Variables from Supplied and Interpolated Spot Variables

4.6.1 Period Variables represent the integrated MWh value over the Settlement Period j. Period variables are evaluated as follows:

The value of the Period Variable F_j for Settlement Period j, is determined by integrating the associated function of time F(t) with respect to time across the Settlement Period.

(a) Where the spot time t_i is the first spot time of the Settlement Period, the value of F(t_i) shall be set to the value of ^HF_ti for the purposes of evaluating the integral.

(b) Where the spot time t_i is the last spot time of the Settlement Period, the value of F(t_i) shall be set to the value of ^LF_ti for the purposes of evaluating the integral.

(c) Where for one or more spot time(s) (t₁, t₂ … t_n) falling within the Settlement Period, the value of F(t_i) remains undefined because two values of ^fF_ti exist for those spot times, and the spot times are neither the first nor last spot times in the Settlement Period, the integral will be evaluated pursuant to 4.6.2.

4.6.2 The integral shall be evaluated as the sum of:

(a) the integral for the period from the first spot time of the Settlement Period to the spot time immediately preceding the first such spot time; plus

(b) the integral from the spot time immediately succeeding the last such spot time to the last spot time of the Settlement Period; plus

(c) the integrals for each of the other periods within the Settlement Period, if any, defined by the interval between the spot time immediately succeeding any such spot time and the spot time immediately preceding the next such spot time.

Table X–1 -Use of Subscripts and Superscripts Applying Except in Relation to Section S

The following subscripts and superscripts are used in the formulae and other algebraic expressions contained in the Code to refer to the following:

Symbol	Parameter
a	Energy Account / Virtual Balancing Account
b	Energy Account
c	Demand Control Instruction
d	Day
e	A particular order number of a ranked System Action
f	Point Value Identification Number
g	A particular System Action
H	The higher of two Point Value Identification Numbers f, specified at the same time t for function ^fF(t)
i	BM Unit
j	Settlement Period
J	Quarter Hour
k	Bid-Offer Acceptance Number
L	The lower of two Point Value Identification Numbers f, specified at time t for function ^fF(t)
m	Calendar month (except in Section T) Balancing Services Adjustment Action (in Section T)
n	Bid-Offer Pair Number
N	Node
p	Trading Party, Contract Trading Party, Imbalance Party or Virtual Lead Party as the case may be
q	The order number of a Ranked Bid Volume or Ranked Offer Volume
r	Trading Unit
s	Market Index Data Provider
S	BSC Season
t	STOR Action Number
u	The Non-Delivery Order Number
v	A particular order number of a ranked System Action
w	System Action, or the order number of a ranked System Action
x	The order number of a Ranked Priced Offer
y	BSC Year
z	Energy Contract Volume Notification or Metered Volume Reallocation Notification as the case may be.
Z	Zone

Table X–2 - Terms and Expressions Applying Except in Relation to Section S

1. Subject to paragraph 2, unless the context otherwise requires, in the Code the words, expressions and acronyms set out in this Table shall bear the respective meanings set out therein.

2. In the fourth column of this Table, words in italics are explanatory only and shall not affect the interpretation of any term in the Table or otherwise of the Code.

Defined Term	Acronym	Units	Definition/Explanatory Text
	α		The number 0.45 as specified in Section T2.2.1(b). The factor α is that proportion of transmission losses to be deducted in total from the BM Unit Metered Volume of BM Units in delivering Trading Units, for the purposes of allocating transmission losses. For the purposes of the above, transmission losses are defined as the sum of BM Unit Metered Volume over all BM Units (with BM Units that import having a negative value of BM Unit Metered Volume)
	QMFR_ziaj	MWh	An Active Energy value in accordance with Section P3.6.2(a). In relation to any BM Unit i, for any Settlement Period j, QMFR_ziaj is a fixed volume of Active Energy to be allocated to the corresponding Energy Account a, of a Contract Trading Party other than the Lead Party from the Energy Account of the Lead Party to which the associated Metered Volume Reallocation Notification z, refers.
	QMPR_ziaj	%	A percentage value in accordance with Section P3.6.2(b). In relation to any BM Unit i, for any Settlement Period j, QMPR_ziaj is a percentage of the BM Unit Metered Volume to be allocated to the corresponding Energy Account a of a Contract Trading Party other than the Lead Party from the Energy Account of the Lead Party to which the associated Metered Volume Reallocation Notification z, refers.
ABSVD BM Unit Delivered Volume	AQVMD_NLKji	MWh	Has the meaning given to it in Annex S-2 paragraph 7.1.1E.
Acceptance Data			Data (in accordance with Section Q5.3.1) to be submitted by the NETSO pursuant to Section Q6.2.1(e).
Acceptance Volume	qA^k_ij(t)	MW	The quantity determined in accordance with Section T3.4. The Acceptance Volume is a quantity of absolute MW for any spot time t obtained by interpolating between Point Acceptance Volumes, qA^k_it, derived from the Acceptance Volume Pairs submitted as part of Acceptance Data for BM Unit i,. and derived from Quarter Hour RR Activations using the Replacement Reserve Schedule Methodology Document.
Acceptance Volume Pair			A pair of data items expressed in accordance with Section Q5.3.1(a) and submitted as part of the Acceptance Data pursuant to Section Q6.2.1(e). The Acceptance Volume Pair is a pair of MW levels each with an associated spot time which describe the absolute MW level at which a BM Unit should operate at those spot times as a result of Acceptance k.
accepted Bid		MWh	Has the meaning given to that term in Annex T-1.
Accepted Bid Volume	qAB^kn_ij(t)	MW	The quantity established in accordance with Section T3.7.2. The Accepted Bid Volume is the quantity of Bid n being the negative part of the Accepted Bid-Offer Volume accepted as a result of Bid-Offer Acceptance k from BM Unit i at spot times t within Settlement Period j.
Accepted Bid-Offer Volume	qABO^kn_ij(t)	MW	The quantity established in accordance with Section T3.6 The Accepted Bid-Offer Volume is the quantity of Bid or Offer from Bid-Offer Pair n accepted as a result of Bid-Offer Acceptance k, that is not flagged as relating to an RR Instruction, in Settlement Period j from BM Unit i, for any spot time t within Settlement Period j
accepted Offer		MWh	Has the meaning given to that term in Annex T-1.
Accepted Offer Volume	qAO^kn_ij(t)	MW	The quantity established in accordance with . T3.7.1. The Accepted Offer Volume is the quantity of Offer n being the positive part of the Accepted Bid-Offer Volume accepted as a result of Bid-Offer Acceptance k from BM Unit i at spot times t within Settlement Period j.
Account Bilateral Contract Volume	QABC_aj	MWh	The quantity determined in accordance with Section P4.1.1. The Account Bilateral Contract Volume is the aggregate of all Energy Contract Volumes relating to Energy Account a in Settlement Period j disregarding those that have been rejected and those contained in Energy Contract Volume Notifications that were refused and represents the energy debited from account a and credited to the other accounts (except in the case of the NETSO) for the purpose of calculating Account Energy Imbalance Volume.
Account Credited Energy Volume	QACE_aj	MWh	The quantity determined in accordance with Section T4.6.1. The Account Credited Energy Volume is the aggregate of the BM Unit Metered Volumes allocated to Energy Account a in Settlement Period j.
Account Energy Imbalance Cashflow	CAEI_aj	£	The amount determined in accordance with Section T4.7.1. The Account Energy Imbalance Cashflow is the total cashflow resulting from the Energy Imbalance of Energy Account a in Settlement Period j such that a negative quantity represents a payment to the Trading Party holding Energy Account a and a positive quantity represents a payment by the Trading Party holding Energy Account a.
Account Energy Imbalance Volume	QAEI_aj	MWh	The quantity determined in accordance with Section T4.6.3. The Account Energy Imbalance Volume is the sum of the Account Credited Energy Volume, plus the Account Period Bid-Offer Volume less the Account Bilateral Contract Volume for Energy Account a, in Settlement Period j.
Account Period Balancing Services Volume	QABS_aj	MWh	The quantity determined in accordance with Section T4.6.2. The Account Period Balancing Services Volume is the sum of the net quantity of all accepted Bids and Offers, and the net energy associated with delivery of Applicable Balancing Services from all BM Units for which Energy Account a is the Lead Energy Account in Settlement Period j.
Activated Quantity		MW	In respect of a Position, the quantity of energy to be activated. Activated Quantity forms part of the Replacement Reserve Activation Data, GB Need Met Data and Interconnector Schedule Data for each Position and is submitted by the NETSO pursuant to Section Q.
Actual Energy Indebtedness	AEI_p	MWh	The amount determined as such in accordance with Section M1.2.5. The Actual Energy Indebtedness is the net energy contribution determined to be allocated to a Trading Party for Settlement Periods as defined in Section M1.2.1.
Arbitrage Tagged			Arbitrage Tagged as provided in paragraph 7 of Part 1 of Annex T-1.
Balancing Demand Control Volume	QBDC_cj	MWh	Has the meaning given to it in Section T3.15.3(b).
Balancing Energy Deviation Price	BEDP_j	£/MWh	The price specified in Section T3.23, being an amount equal to zero.
Balancing Mechanism Window Period			In relation to a particular time, the Balancing Mechanism Window Period is the period from that time to the end of the Settlement Period for which Gate Closure has most recently occurred at that time. The Balancing Mechanism Window Period has a duration of between 1 and 1 ½ hours.
Balancing Services Adjustment Action	m		An individual item in the Balancing Services Adjustment Data for which data is provided pursuant to Section Q6.3.2(b).
Balancing Services Adjustment Buy Action	m		A Balancing Services Adjustment Action for which the Balancing Services Adjustment Volume is positive.
Balancing Services Adjustment Buy Volume	QBSAB^m_j	MWh	The Balancing Services Adjustment Volume in respect of a Balancing Services Adjustment Buy Action.
Balancing Services Adjustment Cost		£	The amount sent by the NETSO as 'Balancing Services Adjustment Cost' in respect of a Balancing Services Adjustment Action in accordance with Section Q6.3.
Balancing Services Adjustment Price	BSAP^m_j	£/MWh	The amount calculated by the SAA and the BMRA as 'Balancing Services Adjustment Price' in respect of a Balancing Services Adjustment Action in accordance with Section Q6.3.
Balancing Services Adjustment Sell Action	m		A Balancing Services Adjustment Action for which the Balancing Services Adjustment Volume is negative.
Balancing Services Adjustment Sell Volume	QBSAS^m_j	MWh	The Balancing Services Adjustment Volume in respect of a Balancing Services Adjustment Sell Action.
Balancing Services Adjustment Volume	QBSA^m_j	MWh	The amount sent by the NETSO as 'Balancing Services Adjustment Volume' in respect of a Balancing Services Adjustment Action in accordance with Section Q6.3.
Bid			The quantity (as provided in Section Q4.1.3(a) or, where applicable, established in Section T3.4B.3) in a Bid-Offer Pair if considered as a possible decrease in Export or increase in Import of the relevant BM Unit at a given time.
Bid Non-Delivery Volume	QNDBⁿ_ij	MWh	The quantity determined in accordance with Section T4.8.10. The Bid Non-Delivery Volume is the quantity of non-delivery apportioned to Bid n from BM Unit i in Settlement Period j.
Bid Price	PBⁿ_ij	£/MWh	The amount in £/MWh associated with a Bid and comprising part of a Bid-Offer Pair.
Bid-Offer Acceptance Number	k		A number used to identify a particular Acceptance.
Bid-Offer Acceptance Time	T^k_it	Spot time	Has the meaning given to that term in Section Q5.1.11.
Bid-Offer Data			Data (comprising the items set out in Section Q4.1.3) to be submitted by the NETSO pursuant to Section Q6.2.1(d).
Bid-Offer Lower Range	BOLRⁿ_ij(t)	MW	The range determined in accordance with Section T3.4A.3, T3.4A.4 or T3.5.2 (as the case may be). The Bid-Offer Lower Range is that data calculated for spot times t in Settlement Period j and BM Unit i, for a Bid-Offer Pair with a negative Bid-Offer Pair Number n. It is used to determine the operating range (in absolute MW) below FPN in which a particular Bid-Offer Pair applies.
Bid-Offer Pair			Data which may be submitted in relation to a BM Unit for a Settlement Period, being data that comprises the items set out in Section Q4.1.3, or (where applicable) data created pursuant to Section T3.4B.1.
Bid-Offer Pair Number	n		A number used to identify a particular Bid-Offer Pair. Values of n are negative for Bid-Offer Pairs that cover operating levels below FPN and positive for those that cover operating levels above FPN.
Bid-Offer Upper Range	BOURⁿ_ij(t)	MW	The range determined in accordance with Section T3.4A.1, T3.4A.2 or T3.5.1 (as the case may be). The Bid-Offer Upper Range is that data calculated for spot times t in Settlement Period j and BM Unit i, for a Bid-Offer Pair with a positive Bid-Offer Pair Number n. It is used to determine the operating range (in absolute MW) above FPN in which a particular Bid-Offer Pair applies.
Bid-Offer Volume	qBOⁿ_ij(t)	MW	The quantity established in accordance with Section T3.3Section T3.3 The Bid-Offer Volume is the quantity of power increase or decrease available (relative to FPN) from Bid-Offer Pair n, in Settlement Period j for BM Unit i at spot time t. Initially the Bid-Offer Volume for a Bid-Offer Pair is constant across a particular Settlement Period.
BM Unit Allocated Demand Disconnection Volume	BMUADDV_ij	MWh	The quantity submitted in accordance with paragraph 9.6.2 of Annex S-2.
BM Unit Allocated Demand Volume	BMUADV_ij	MWh	The quantity submitted in accordance with paragraph 9.6.2 of Annex S-2.
BM Unit Applicable Balancing Services Volume Data or BM Unit ABSVD	QAS_ij	MWh	In respect of a BM Unit and a Settlement Period, the Applicable Balancing Services Volume Data sent by the NETSO to the SAA pursuant to Section Q6.4.1.
BM Unit Credit Assessment Export Capability	BMCAEC_i	MW	The quantity determined in accordance with Section M1.6.1(a).
BM Unit Credit Assessment Import Capability	BMCAIC_i	MW	The quantity determined in accordance with Section M1.6.1(b).
BM Unit Identification Number	i		A unique identifier for each BM Unit.
BM Unit Metered Volume	QM_ij	MWh	In respect of a Settlement Period: (i) in relation to a BM Unit (other than an Interconnector BM Unit) comprising CVA Metering Systems, the Metered Volume (as determined in accordance with Section R); (ii) in relation to an Interconnector BM Unit of an Interconnector User, the quantity determined in accordance with Section R7.4.2 (but without prejudice to Section T1.4.6); (iii) in relation to an Interconnector BM Unit allocated to an Interconnector Error Administrator, the quantity determined in accordance with Section T4.1; and (iv) in relation to a Supplier BM Unit, the quantity determined in accordance with Section T4.2.1 and (v) in relation to a Secondary BM Unit, the quantity determined in accordance with Section T4.2A.1.
BM Unit MSID Pair Data			Has the meaning given to that term in Section S paragraph 10.1.3.
BM Unit Period Non-Delivery Charge	CND_ij	£	The amount determined in accordance with Section T4.8.13. The BM Unit Period Non-Delivery Charge is the total non-delivery charge associated with the non-deliver of Bids or Offers for BM Unit i in Settlement Period j.
Buy Price Price Adjustment	BPAj	£/MWh	The amount sent by the NETSO as the ‘Buy Price Price Adjustment’ in accordance with Section Q6.3.
CADL Flagged			CADL Flagged as provided in paragraph 3 of Part 1 of Annex T-1.
Classified Ranked Set			One of the Classified Ranked Sets as provided in paragraph 8 of Part 1 of Annex T-1.
Continuous Acceptance Duration	CAD^k_i	Minutes	Has the meaning given to that term in paragraph 12.3 of Annex T-1.
Continuous Acceptance Duration Limit	CADL	Minutes	The value established and from time to time revised and approved in accordance with Section T1.9.
Corrected Component	CORC_iNj	MWh	The quantity submitted in accordance with paragraph 9.3.3 of Annex S-2.
Corrected MSID ABSVD Component	CORABSVDC_i2Nj		Has the meaning given to it in Annex S-2 paragraph 9.3.5.
Credit Assessment Credited Energy Volume	CAQCE_iaj	MWh	The amount determined in accordance with Section M1.2.3. The Credit Assessment Credited Energy Volume is the contribution to a Trading Party’s Credit Assessment Energy Indebtedness from BM Unit i and Energy Account a in Settlement Period j.
Credit Assessment Energy Indebtedness	CEI_pj	MWh	The amount determined as such in accordance with Section M1.2.2. The Credit Assessment Energy Indebtedness is the net energy contribution determined to be allocated to a Trading Party for Settlement Periods as defined in Section M1.2.1.
Credit Cover	CC_p	£	Is defined in Annex X-1
Credit Cover Error Compensation	CCEC_p	£	Has the meaning given to that term in Section M4.1.1. The Credit Cover Error Compensation is the aggregate payment that may be made to a Trading Party in relation to a Credit Cover Error.
Credit Cover Error Erroneous Rejection Flag	FLAG_pj		Has the value determined in accordance with Section M4.2.3. The Credit Cover Error Erroneous Rejection Flag is a flag indicating whether Settlement Period j was determined erroneously to fall within a Credit Default Rejection Period for Trading Party p.
Credit Cover Error Imbalance Amount	ECB_pj	£	The amount determined as such in accordance with Section M4.2.3. The Credit Cover Error Imbalance Amount represents the Energy Imbalance related compensation that may be paid to a Trading Party in relation to Settlement Period j, as a consequence of a Credit Cover Error.
Credit Cover Error Interest Amount	ECA_pj	£	The amount determined as such in accordance with Section M4.2.2. The Credit Cover Error Interest Amount represents the interest related compensation that may be paid to a Trading Party in relation to Settlement Period j, as a consequence of a Credit Cover Error.
Credit Cover Error Rejection Volume	REJ_aj	MWh	The quantity determined in accordance with Section M4.2.3. The Credit Cover Error Rejection Volume represents an assessment of the change (whether positive or negative) in the quantity of energy that would have been allocated to Energy Account a, of Trading Party P, in Settlement Period j, had Energy Contract Volume Notifications and Data relating to Metered Volume Reallocation Notifications not been rejected in accordance with Sections P2.5.2, and P3.5.2, by virtue of Trading Party P being in Level 2 Credit Default.
Credit Cover Percentage	CCP_pj	%	Has the meaning given to that term in Section M3.1.1.
Credited Energy Volume	QCE_iaj	MWh	The quantity determined in accordance with Section T4.5.1.
Daily Party BM Unit Cashflow	CBM_p	£	The amount determined in accordance with Section T3.12.2.
Daily Party Energy Imbalance Cashflow	CAEI_p	£	The amount determined in accordance with Section T4.7.3.
Daily Party Information Imbalance Charge	CII_p	£	The amount determined in accordance with Section T4.3.8.
Daily Party Non-Delivery Charge	CND_p	£	The amount determined in accordance with Section T4.8.15
Daily Party Residual Settlement Cashflow	RCRC_p	£	The amount determined in accordance with Section T4.10.4.
Daily Party RR Cashflow	CRR_p	£	The amount determined in accordance with T3.25.2.
Daily Party RR Instruction Deviation Cashflow	CDR_p	£	The amount determined in accordance with T3.25.3.
Daily System Operator Cashflow	CSO	£	The amount determined in accordance with Section T4.9.2.
DC Limits		MW and/or %	Is defined in Section X-1.
De Minimis Acceptance Threshold	DMAT	MWh	The value established and from time to time revised and approved in accordance with Section T1.8.
De Minimis Tagged			De Minimis Tagged as provided in paragraph 6 of Part 1 of Annex T-1.
Deemed Standard Product Bid Volume	qDSPB^J_ij(t)	MW	The quantity established in accordance with Section T3.19.2. The Deemed Standard Product Bid Volume is the quantity of Bid being the negative part of the Deemed Standard Product Volume created as a result of a Quarter Hour RR Activation from BM Unit i at spot times t in Quarter Hour J.
Deemed Standard Product Offer Volume	qDSPO^J_ij(t)	MW	The quantity established in accordance with Section T3.19.1. The Deemed Standard Product Offer Volume is the quantity of Offer being the positive part of the Deemed Standard Product Volume created as a result of a Quarter Hour RR Activation from BM Unit i at spot times t in Quarter Hour J.
Deemed Standard Product Point Variables	qDSP^J_ijt	MW	A MW level and associated time created in accordance with Section T3.1.5(c). A Point Acceptance Volume, created from Quarter Hour RR Activation Data, is a level in absolute MW for spot time t and BM Unit i, used to imply the acceptance of one or more Replacement Reserve Bids.
Deemed Standard Product Shape	qDSP^J_ij(t)	MW	The quantity established in accordance with Section T3.17.1. The Deemed Standard Product Shape is a quantity of absolute MW for any spot time t obtained by interpolating between Deemed Standard Product Point Variables, qDSP^J_ijt, derived from the Quarter Hour RR Activation Data submitted as part of the Quarter Hour Auction Result Data for an Replacement Reserve Auction Period
Deemed Standard Product Volume	qDSPV^J_ij(t)	MW	The quantity established in accordance with Section T3.18.1. The Deemed Standard Product Volume is the quantity of Bid or Offer accepted as a result of a Quarter Hour RR Activation from BM Unit i at spot times t in Quarter Hour J.
Default Funding Share	FSD_pm		Has the meaning given to that term in Section D1.3.1(b).
Delivering Transmission Losses Adjustment.	TLMO⁺_j		The factor determined as such in accordance with Section T2.3.1. The factor used in the determination of the Transmission Loss Multiplier for BM Units in Delivering Trading Units in Settlement Period j
De-Rated Margin Forecast		MWh	The forecast submitted in accordance with Section Q6.1.25.
Emergency Acceptance			An Acceptance which falls within Section Q5.1.3(b).
Emergency Flagged Ranked Set			One of the Emergency Flagged Ranked Sets as provided in paragraph 5 of Part 1 of Annex T-1.
End Point Demand Control Level		MW	Has the meaning given to that term in Section T3.15(b).
Energy Contract Volume	ECQ_zabj	MWh	An Active Energy value in accordance with Section P2.6.1.
Energy Credit Cover	ECC_p	MWh	Has the meaning given to that term in Section M2.4.1.
Energy Indebtedness	EI_pj	MWh	Has the meaning given to that term in Section M1.2.1.
Erroneous Energy Indebtedness	EEI_pj	MWh	The amount determined as such in accordance with Section M4.2.2. The Erroneous Energy Indebtedness represents an assessment of that amount of Energy Credit Cover that a Trading Party would have had to establish in Settlement Period j, in order to avoid being in level 1 credit default based on the erroneous calculation of Energy Indebtedness.
Final Loss of Load Probability	LoLP_j		In relation to a Settlement Period, the final probability to be provided by the NETSO in accordance with the Loss of Load Probability Calculation Statement and Section Q6.7.2 or Q6.8.4, as applicable.
Final Ranked Set			The Final Ranked Set as provided in paragraph 11.3 of Part 1 of Annex T-1.
First-Stage Flagged			First-Stage Flagged in accordance with paragraph 3, 4 or 5 of Part 1 of Annex T-1.
Flagged (and Unflagged)			Have the meanings given to those terms in paragraph 1.4 of Annex T-1.
Flow Direction			Indicates the direction of the flow of energy associated with a Position. Flow Direction forms part of the Replacement Reserve Activation Data, GB Need Met Data and Interconnector Schedule Data for each Position and is submitted by the NETSO pursuant to Section Q.
Forecast Total Power Park Module Generation		MW	The forecast of total generation across all Power Park Modules metered by the NETSO in accordance with CC6.5.6 of the Grid Code.
FPN	FPN_ij(t)	MW	The quantity established in accordance with Section T3.2.1. The final physical notification for BM Unit is the level of import or export (as the case may be) that the Party expects to import or export from BM Unit i, in Settlement Period j, in the absence of any Balancing Mechanism Acceptances from the NETSO. The value of FPN_ij(t) is calculated for spot times t in Settlement Period by linear interpolation from the discrete values of Point FPN submitted.
GB Need Met Data			Data (comprising the items set out in Section Q5.6.3) to be submitted by the NETSO pursuant to Section Q6.2C.1(d).
GC Limits		MW and/or %	Is defined in Section X-1.
General Funding Share	FSG_pm		Has the meaning given to that term in Section D1.2.1(d). In relation to month m, a Trading Party’s General Funding Share reflects its proportionate share of the aggregate of certain BSCCo Charges for that month.
Generating Plant Demand Margin	OCNMFD or OCNMFW	MW	Has the meaning given to that term in OC2 of the Grid Code.
Generic Line Loss Factor			A Line Loss Factor established for a class of Metering System as provided for in Section K1.7.2.
Gross Contract MWh		MWh	The value established in accordance with Annex D-3 paragraph 3.2. The Gross Contract MWh is the gross aggregate of all Energy Contract Volumes and Metered Volume Fixed Reallocations relating to a Trading Party over a given month.
GSP Group Metered Volume		MWh	In relation to any GSP Group and any Settlement Period, a Metered Volume representing the algebraic sum of: (i) the quantity of Active Energy flowing into a GSP Group at Grid Supply Points connected to that GSP Group and at Distribution Systems Connections Points connected to that GSP Group, and (ii) the quantity of Active Energy flowing out of a GSP Group at Grid Supply Points connected to that GSP Group and at Distribution Systems Connections Points connected to that GSP Group but disregarding Exports and Imports at Boundary Points in that GSP Group.
GSP Group Take		MWh	In relation to any GSP Group and any Settlement Period, shall be determined as follows: GSPGT = GMV + I – E where: GSPGT means the GSP Group Take for that GSP Group and that Settlement Period; GMV means the GSP Group Metered Volume for that GSP Group and that Settlement Period; I means the magnitude of the quantities of Imports at CVA Boundary Points in that GSP Group (as at the Transmission Boundary) for that Settlement Period; and E means the magnitude of the quantities of Exports at CVA Boundary Points in that GSP Group (as at the Transmission Boundary) for that Settlement Period.
High Reference Temperature		Degrees celsius	The daily average temperature for Great Britain which was exceeded on 12% of days during a 30 year historic period.
High Reference Transmission Energy		MWh	The daily aggregate Transmission Energy which was exceeded on 12% of days during a 30 year historic period.
Indicated Constraint Boundary Margin	MELNGC	MW	The import and export constraint limits for a BMRS Zone. The import constraint limit being calculated as the boundary transfer limit minus the Demand Forecast plus the sum of Maximum Export Limits for exporting BM Units and the export constraint limit being calculated as the boundary transfer limit plus the Demand Forecast minus the sum of Maximum Export Limits for exporting BM Units
Indicated Demand	INDDEM	MW	The half-hour average MW expected demand in each Settlement Period calculated as the sum of all Physical Notifications for that Settlement Period prevailing at the time of the forecast and for BM Units for which the Physical Notifications are negative, i.e. will be importing energy.
Indicated Generation	INDGEN	MW	The half-hour average MW expected generation in each Settlement Period calculated as the sum of all Physical Notifications for that Settlement Period prevailing at the time of the forecast and for BM Units for which the Physical Notifications are positive, i.e. will be exporting energy.
Indicated Imbalance	IMBALNGC	MW	Has the meaning given to that term in the Grid Code. Calculated as the difference between the sum of all Physical Notifications for exporting BM Units (i.e. the Indicated Generation) and the Transmission System Demand forecast
Indicated Margin		MW	Has the meaning given to that term in the Grid Code. Calculated as the difference between the sum of all Maximum Export Limits for exporting BM Units and the Transmission System Demand forecast
Indicative Loss of Load Probability			In relation to a Settlement Period, the indicative probability to be provided by the NETSO in accordance with the Loss of Load Probability Calculation Statement and Sections Q6.8.2 and Q6.8.3.
Indicative Net Imbalance Volume	INIV_j	MWh	The Indicative Net Imbalance Volume calculated in accordance with Section V2.6.5.
Indicative Period Accepted Bid Volume	IRRAB^kn_ij	MWh	The quantity determined in accordance with Section V2.6.4
Indicative Period Accepted Offer Volume	IRRAO^kn_ij	MWh	The quantity determined in accordance with Section V2.6.4
Indicative Period Balancing Mechanism Bid Cashflow	ICBⁿ_ij	£	The amount determined in accordance with Section V2.6.6.
Indicative Period Balancing Mechanism Offer Cashflow	ICOⁿ_ij	£	The amount determined in accordance with Section V2.6.6.
Indicative Period BM Unit Total Accepted Bid Volume	IQABⁿ_ij	MWh	The quantity determined in accordance with Section V2.6.4
Indicative Period BM Unit Total Accepted Offer Volume.	IQAOⁿ_ij	MWh	The quantity determined in accordance with Section V2.6.4
Indicative Period RR BM Unit Cashflow	ICRR_iJ	£	The quantity determined in accordance with Section V2.6.6A
Indicative Period RR Total Accepted Bid Volume	IRRABⁿ_ij	MWh	The quantity determined in accordance with Section V2.6.4
Indicative Period RR Total Accepted Offer Volume	IRRAOⁿ_ij	MWh	The quantity determined in accordance with Section V2.6.4
Indicative Quarter-Hour RR Cashflow	ICCR_iJ	£	The quantity determined in accordance with Section V2.6.6A
Indicative System Buy Price	ISBP_j	£/MWh	The Indicative System Buy Price calculated in accordance with Section V2.6.5.
Indicative System Sell Price	ISSP_j	£/MWh	The Indicative System Sell Price calculated in accordance with Section V2.6.5.
Information Imbalance Charge	CII_ij	£	The amount determined in accordance with Section T4.3.6. The Information Imbalance Charge is the charge applicable to the associated Lead Party as a result of the difference in FPN data as modified by Acceptances and BM Unit Metered Volume from BM Unit i in Settlement Period j.
Information Imbalance Price	IIP_j	£/MWh	The price specified in Section T4.3.5, being an amount equal to zero.
Initial Energy Credit Cover	IECC_p	MWh	The amount determined as such in accordance with Section M4.2.2. The Initial Energy Credit Cover is the amount of Credit Cover that a Trading Party p has in place at the start of a Credit Cover Error Period.
Initial National Demand Out-Turn	INDO	MW	The demand metered by the NETSO taking into account transmission losses but not including station transformer load, pumped storage demand or Interconnector demand. References to INDO in Section Q6.1.13 and in Table 1 of Section V Annex V-1 mean the half-hour average INDO for a Settlement Period. References to INDO in Section G3.1.4 mean the spot time INDO measured by the NETSO in accordance with that paragraph.
Initial Ranked Set			One of the Initial Ranked Sets of System Actions as provided in paragraph 2.1(c) of Part 1 of Annex T-1.
Initial Transmission System Demand Out-Turn	ITSDO	MW	The half-hour average MW demand metered by the NETSO taking into account transmission losses and including station transformers load, pumped storage demand and Interconnector demand.
Interconnector Metered Volume	IMV_j	MWh	Is defined in Annex X-1. The net aggregate volume of Active Energy, determined as at the Transmission System Boundary, which flowed from or to the relevant Interconnector in Settlement Period j.
Interconnector Schedule Data			Data (comprising the items set out in Section Q5.6.4) to be submitted by the NETSO pursuant to Section Q6.2C.1(d).
Line Loss Factor			Means a multiplier which, when applied to data from a CVA Metering System connected to a Boundary Point on a Distribution System, converts such data into an equivalent value at the Transmission System Boundary.
Line Loss Factor Class	LLFC		A set of SVA Metering Systems defined by a Licensed Distribution System Operator relating to any one or more of its Distribution System(s) that are assigned the same Line Loss Factor for the relevant Settlement Period.
Loss of Load Probability			In relation to a Settlement Period, the Final Loss of Load Probability or the Indicative Loss of Load Probability as the context so requires.
Low Reference Temperature		Degrees celsius	The daily average temperature for Great Britain which was exceeded on 88% of days during a 30 year historic period.
Low Reference Transmission Energy		MWh	The daily aggregate Transmission Energy which was exceeded on 88% of days during a 30 year historic period.
Main Funding Share	FSM_pm		Has the meaning given to that term in Section D1.2.1(a). The Main Funding Share represents a Trading Party’s proportionate share of the aggregate Credited Energy Volumes for month m.
Market Index Price	PXP_sj	£/MWh	In relation to a Market Index Data Provider and a Settlement Period, the price data to be provided by that Market Index Data Provider in accordance with the Market Index Definition Statement or (where applicable) deemed in accordance with Section T4.3A.1.
Market Index Volume	QXP_sj	MWh	In relation to a Market Index Data Provider and a Settlement Period, the volume data to be provided by that Market Index Data Provider in accordance with the Market Index Definition Statement or (where applicable) deemed in accordance with Section T4.3A.1.
Market Price	MP_j	£/MWh	Has the meaning given to that term in Section T4.3A.2.
Maximum Delivery Period			Has the meaning given to that term in BC1 of the Grid Code.
Maximum Delivery Volume			Has the meaning given to that term in BC1 of the Grid Code.
Maximum Export Limit			Has the meaning given to that term in BC1 of the Grid Code.
Maximum Import Limit			Has the meaning given to that term in BC1 of the Grid Code.
Metered Credit Assessment Credited Energy Volume	MAQCE_iaj	MWh	is defined in Section M1.2.4A. The Metered Credit Assessment Credited Energy Volume is the contribution to a Trading Party’s Metered Energy Indebtedness from BM Unit i and Energy Account a in Settlement Period j.
Metered Energy Indebtedness	MEI_pj	MWh	is defined in Section M1.2.4A. The Metered Energy Indebtedness is the net energy contribution determined to be allocated to a Trading Party for Settlement Periods as defined in Section M1.2.4A.
Metered Volume Fixed Reallocation	QMFR_iaj	MWh	A MWh value determined in accordance with Section P4.3.1. In relation to any BM Unit i, for any Settlement Period j, Metered Volume Fixed Reallocation means, for Energy Account a of a Contract trading Party, the aggregate of all Metered Volume Reallocation Notification Fixed Data for Metered Volume Reallocation Notifications relating to such Energy Account.
Metered Volume Percentage Reallocation	QMPR_iaj	%	A percentage value determined in accordance with Section P4.3.1. In relation to any BM Unit i, for any Settlement Period j, Metered Volume Percentage Reallocation means, for Energy Account a of Contract Trading Party, the aggregate of all Metered Volume Reallocation Notification Percentage Data for Metered Volume Reallocation Notifications relating to such Party.
Minimum Non-Zero Time			Has the meaning given to that term in BC1 of the Grid Code.
Minimum Zero Time			Has the meaning given to that term in BC1 of the Grid Code.
Monthly Consumption-Charging Net SVA Costs	MCNSC_m	£	Has the meaning given to that term in Section D4.1(d).
Monthly Default Costs	MDC_m	£	Has the meaning given to that term in Section D4.1(e).
Monthly Net Main Costs	MNMC_m	£	Has the meaning given to that term in Section D4.1(d).
Monthly payment	P_pm	£	Has the meaning given to that term in Annex D4 1.1.
Monthly Production-Charging SVA Costs	MPSC_m	£	Has the meaning given to that term in Section D4.1(d).
MSID Pair Data			The data comprising the data items pursuant to Section S10.1 and may be: (i) BM Unit MSID Pair Data; or (ii) Non BM Unit ABSVD MSID Pair Data
MSID Pair Delivered Volume	MPDV	MWh	The amount determined in accordance with Section Q6.4.10 or S11.1.1. .MSID Pair Delivered Volume is such volumes of Active Energy notified to the SVAA by the NETSO for the purposes of calculating Non BM Unit ABSVD (SNBABSVD_ij); or by the Virtual Lead Party for the purposes of aggregating Secondary BM Unit Supplier Delivered Volume (VBMUSDV_iZj).
National Demand			Has the meaning given to the term National Demand as defined in the Grid Code.
Net Imbalance Volume	NIV_j	MWh	Has the meaning given to that term in paragraph 14.1 of Annex T-1.
NIV Tagged			NIV Tagged as provided in paragraph 9 of Part 1 of Annex T-1.
Non BM Unit Applicable Balancing Services Volume Data or Non BM Unit ABSVD			The following data: (i) Non BM Unit ABSVD MSID Pair Data ; (ii) the associated MSID Pair Delivered Volume.
Non BM Unit ABSVD MSID Pair Data			Has the meaning given to that term in Section Q paragraph 6.4.8.
Non-BM STOR Instructed Volume		MWh	The volume of Short Term Operating Reserve instructed by the NETSO outside of the balancing mechanism in order to increase generation or reduce demand.
Non-BM STOR Instruction			A Short Term Operating Reserve instruction given by the NETSO outside of the balancing mechanism in order to increase generation or reduce demand.
Non-Delivered Bid Charge	CNDBⁿ_ij	£	The amount determined in accordance with Section T4.8.12. The Non-Delivered Bid Charge is a charge in Settlement Period j, that may relate to an accepted Bid n, that is determined not to have been delivered (either wholly or in part) from BM Unit i.
Non-Delivered Bid Price	NDPBⁿ_ij	£/MWh	The amount determined in accordance Section T4.8.19, T4.8.20 and T4.8.21. The amount in £/MWh associated with an Accepted Bid (being an Accepted Bid or a downward Quarter Hour RR Activation) that is allocated to Period BM Non-Delivered Bid Volume.
Non-Delivered Offer Charge	CNDOⁿ_ij	£	The amount determined in accordance with Section T4.8.11. The Non-Delivered Offer Charge is a charge in Settlement Period j, that may relate to an accepted Offer n, that is determined not to have been delivered (either wholly or in part) from BM Unit i.
Non-Delivered Offer Price	NDPOⁿ_ij	£/MWh	The amount determined in accordance Section T4.8.16, T4.8.17 and T4.8.18. The amount in £/MWh associated with an Accepted Offer (being an Accepted Offer or an upward Quarter Hour RR Activation) that is allocated to Period BM Non-Delivered Offer Volume.
Non-Delivery Order Number	u		The number allocated to an Offer or Bid in accordance with Section T4.8.4 or T4.8.8. The Non-Delivery Order Number (u) is an index used to rank non-delivered Offers or Bids from a BM Unit in a particular Settlement Period in order to determine the order of allocation the Period BM Unit Non-Delivered Offer Volume, or the Period BM Unit Non-Delivered Bid Volume.
Non-Working Day Credit Assessment Load Factor	NWDCALF_i		Is defined in Annex X-1. The factor is used to establish the BM Unit Credit Assessment Export Capability and BM Unit Credit Assessment Import Capability for BM Uniti on a CALF Non-Working Day determined for the purposes of Credit Assessment Load Factor.
Normal Reference Temperature		Degrees celsius	The daily average temperature for Great Britain which was exceeded on 50% of days during a 30 year historic period.
Normal Reference Transmission Energy		MWh	The daily aggregate Transmission Energy which was exceeded on 50% of days during a 30 year historic period.
Notice to Deliver Bids			Has the meaning given to that term in BC1 of the Grid Code.
Notice to Deliver Offers			Has the meaning given to that term in BC1 of the Grid Code.
Notice to Deviate from Zero			Has the meaning given to that term in BC1 of the Grid Code.
Offer			The quantity (as provided in Section Q4.1.3(a) or, where applicable, established in Section T3.4B.3) in a Bid-Offer Pair if considered as a possible increase in Export or decrease in Import of the relevant BM Unit at a given time.
Offer Non-Delivery Volume	QNDOⁿ_ij	MWh	The quantity determined in accordance with Section T4.8.6. The Offer Non-Delivery Volume is the quantity of non-delivery apportioned to Offer n from BM Unit i in Settlement Period j.
Offer Price	POⁿ_ij	£/MWh	The amount in £/MWh associated with an Offer and comprising part of a Bid-Offer Pair.
Offtaking Transmission Losses Adjustment	TLMO^-_j		The factor determined as such in accordance with Section T2.3.1. The factor used in the determination of the Transmission Loss Multiplier for BM Units in Offtaking in Trading Units in Settlement Period j
Output Usable		MW	Has the meaning given to that term in the Grid Code.
Out-Turn Temperature		Degrees celsius	A single value deemed to be representative of the temperature for Great Britain as measured at midday.
PAR Tagged			PAR Tagged as provided in paragraph 11 of Part 1 of Annex T-1.
Party Daily Reallocation Proportion			Has the meaning given to that term in Section G1.3.
Period Accepted Bid Volume	QAB^kn_ij	MWh	The quantity established in accordance with Section T3.8.2. The Period Accepted Bid Volume is the volume of Bid n, accepted in respect of BM Unit i, in Settlement Period j, as a result of Acceptance k, where that Acceptance is not flagged as relating to an RR Schedule.
Period Accepted Offer Volume	QAO^kn_ij	MWh	The quantity established in accordance with Section T3.8.1. The Period Accepted Offer Volume is the volume of Offer n, accepted in respect of BM Unit i, in Settlement Period j as a result of Acceptance k, where that Acceptance is not flagged as relating to an RR Schedule.
Period BM Unit Balancing Services Volume	QBS_ij	MWh	The quantity determined in accordance with Section T4.3.2. The Period BM Unit Balancing Services Volume is the sum of the net quantity of accepted Bids and Offers and the net quantity of energy associated with delivery of Applicable Balancing Services from BM Unit i in Settlement Period j.
Period BM Unit Bid Cashflow	CBⁿ_ij	£	The amount determined in accordance with Section T3.10.2. The Period BM Unit Bid Cashflow is the total cashflow resulting from accepted volumes of Bid n from BM Unit i in Settlement Period j.
Period BM Unit Cashflow	CBM_ij	£	The amount determined in accordance with Section T3.11.1. The Period BM Unit Cashflow is the total cashflow resulting from all accepted Bids and Offers from BM Unit i in Settlement Period j.
Period BM Unit Demand Disconnection Volume	QDD_ij	MWh	The quantity established in accordance with Section R8.2.1. The Period BM Unit Demand Disconnection Volume is the volume of energy for BM Unit i in Settlement Period j that was subject to Demand Disconnection.
Period BM Unit Non-Delivered Bid Volume	QNDB_ij	MWh	The quantity determined in accordance with Section T4.8.2. The Period BM Unit Non-Delivered Bid Volume is the quantity of non-delivered Bids from BM Unit i in Settlement Period j.
Period BM Unit Non-Delivered Offer Volume	QNDO_ij	MWh	The quantity determined in accordance with Section T4.8.1. The Period BM Unit Non-Delivered Offer Volume is the quantity of non-delivered Offers from BM Unit i in Settlement Period j.
Period BM Unit Offer Cashflow	COⁿ_ij	£	The amount determined in accordance with Section T3.10.1. The Period BM Unit Offer Cashflow is the total cashflow resulting from accepted volumes of Offer n from BM Unit i in Settlement Period j.
Period BM Unit Total Accepted Bid Volume	QABⁿ_ij	MWh	The quantity established in accordance with Section T3.9.2. The Period BM Unit Total Accepted Bid Volume is the quantity of Bid n, accepted in respect of BM Unit i, in Settlement Period j, as a result of all Acceptances that are not flagged as relating to an RR Schedule.
Period BM Unit Total Accepted Offer Volume	QAOⁿ_ij	MWh	The quantity established in accordance with Section T3.9.1. The Period BM Unit Total Accepted Offer Volume is the quantity of Offer n, accepted in respect of BM Unit i, in Settlement Period j, as a result of all Acceptances that are not flagged as relating to an RR Schedule.
Period Deemed Standard Product Bid Volume	DSPB^J_ij	MWh	The quantity established in accordance with Section T3.20.2. The Period Deemed Standard Product Bid Volume is the volume of Bid, accepted in respect of BM Unit i, in Settlement Period j as a result of an acceptance of a Replacement Reserve Bid in Quarter Hour J.
Period Deemed Standard Product Offer Volume	DSPO^J_ij	MWh	The quantity established in accordance with Section T3.20.1. The Period Deemed Standard Product Offer Volume is the volume of Offer, accepted in respect of BM Unit i, in Settlement Period j as a result of an acceptance of a Replacement Reserve Bid in Quarter Hour J.
Period Expected Metered Volume	QME_ij	MWh	The quantity determined in accordance with Section T4.3.3. The Period Expected Metered Volume is the quantity of energy that a particular BM Unit i, is expected to export or import in Settlement Period j, after taking account of any accepted offers or bids.
Period FPN	FPN_ij	MWh	The quantity determined in accordance with T4.3.1. The Period FPN is the integrated MWh of energy implied by integrating the Final Physical Notification for BM Unit i over Settlement Period j.
Period Information Imbalance Volume	QII_ij	MWh	The quantity determined in accordance with Section T4.3.4. The Period Information Imbalance Volume is the difference between the BM Unit Metered Volume and the Period Expected Metered Volume for BM Unit i in Settlement Period j.
Period RR Accepted Bid Volume	RRAB^kn_ij	MWh	The quantity established in accordance with Section T3.8.4. The Period RR Accepted Bid Volume is the volume of Bid n, accepted in respect of BM Unit i, in Settlement Period j, as a result of Acceptance k, where that Acceptance is flagged as relating to an RR Schedule.
Period RR Accepted Offer Volume	RRAO^kn_ij	MWh	The quantity established in accordance with Section T3.8.3. The Period RR Accepted Offer Volume is the volume of Offer n, accepted in respect of BM Unit i, in Settlement Period j as a result of Acceptance k, where that Acceptance is flagged as relating to an RR Schedule.
Period RR BM Unit Cashflow	CRR_ij	£	The amount determined in accordance with Section T3.11A.3. The Period RR BM Unit Cashflow is the total cashflow resulting from all Quarter Hour RR Activations from BM Unit i in Settlement Period j.
Period RR Total Accepted Bid Volume	RRABⁿ_ij	MWh	The quantity established in accordance with Section T3.9.4. The Period RR Total Accepted Bid Volume is the quantity of Bid n, accepted in respect of BM Unit i, in Settlement Period j, as a result of all Acceptances that are flagged as relating to an RR Schedule.
Period RR Total Accepted Offer Volume	RRAOⁿ_ij	MWh	The quantity established in accordance with Section T3.9.3. The Period RR Total Accepted Offer Volume is the quantity of Offer n, accepted in respect of BM Unit i, in Settlement Period j, as a result of all Acceptances that are flagged as relating to an RR Schedule.
Period Secondary BM Unit Delivered Proportion	SP_iji2	MWh	This quantity is determined in accordance with Section T4.3B.3.
Period Secondary BM Unit Delivered Volume	QSD_ij _or QSD_i2j	MWh	This quantity is determined in accordance with Section T4.3B.2. This quantity is represented by the acronym QSD_i2jin paragraph T4.3B.4 for the sole reason that the formula in this paragraph refers to both Primary BM Units and Secondary BM Units.
Period Secondary BM Unit Non-Delivered Volume	QSND_ij	MWh	This quantity is determined in accordance with Section T4.3B.1.
Period Secondary BM Unit Supplier Delivered Volume	QSD_iji2	MWh	This quantity is determined in accordance with Section T4.3B.4.
Period Supplier BM Unit Delivered Volume	QBSD_ij	MWh	This quantity is determined in accordance with Section T4.3B.5.
Point Acceptance Volume	qA^k_it	MW	A MW level and associated time created in accordance with Section T3.1.2(c) A Point Acceptance Volume submitted as part of Acceptance Volume Pair, is a level in absolute MW for spot time t and BM Unit i, used to imply the acceptance of one or more Offers and/or Bids.
Point Bid-Offer Volume	^fqBOⁿ_ijt	MW	A MW level and associated time in accordance with Section T3.1.2(b). The Point Bid-Offer Volume is one of two MW quantities each with the same or different associated spot time t, determined for each Bid-Offer Pair n, for BM Unit i in Settlement Period j.
Point FPN	^fFPN_ijt	MW	A MW quantity and associated time in accordance with Section T3.1.2(a). Point FPN data is a series of one or more MW spot values submitted for spot times t in Settlement Period j for BM Unit i. It is used to determine the values of Final Physical Notification.
Point Value Identification Number	f		A number used to differentiate two values of a point variable determined for the same spot time and established for Point FPN values in Section T3.1.2(a) and for Point Bid-Offer Volumes in Section T3.1.2(b).
Position			The identifier for a specific period of time submitted to the SAA pursuant to Section T3.1.5 with associated Replacement Reserve Activation Data, GB Need Met Data and Interconnector Schedule Data. Each Position is an identifier determined by reference to a Replacement Reserve Auction Period Resolution Type. For a PT60 there will be one Position associated with the relevant Replacement Reserve Auction Period, for a PT30 there will be two Positions associated with the relevant Replacement Reserve Auction Period and for a PT15 there will be four Positions associated with the relevant Replacement Reserve Auction Period. The SAA will convert Replacement Reserve Activation Data, GB Need Met Data and Interconnector Schedule Data associated with each Position into Quarter Hour data pursuant to Section T3.1.5.
Price Average Reference Volume	PAR	MWh	The volume determined in accordance with Section T1.10.1
Quarter Hour			A period of 15 minutes beginning on the hour or each quarter hour thereafter and in accordance with paragraph 4.3A of this Annex X-2.
Quarter Hour GB Need Met			For each Quarter Hour, data derived from GB Need Met Data pursuant to paragraph T3.1.5.
Quarter Hour Interconnector Schedule			For each Quarter Hour, data derived from Interconnector Schedule Data pursuant to paragraph T3.1.5.
Quarter Hour RR Activated Quantity			For each Quarter Hour, the MW level derived from Replacement Reserve Auction Result Data pursuant to paragraph T3.1.5.
Quarter Hour RR Activation			For each Quarter Hour, data derived from Replacement Reserve Activation Data pursuant to paragraph T3.1.5.
Quarter Hour RR Activation Data			Data (comprising the items set out in Section Q5.6.2) to be submitted by the NETSO pursuant to Section Q6.2C.1(d).
Quarter Hour RR Activation Price		£/MWh	The price associated with a RR Activation as defined in Section Q5.6.2(e).
Quarter Hour RR Activation Volume	RRAV_iJ	MWh	The quantity established in accordance with Section T3.9.5. The RR Activation Level multiplied by the Quarter Hour duration in hours, for a given Quarter Hour RR Activation.
Quarter Hour RR Cashflow	CCR_iJ	£	The amount determined in accordance with Section T3.11A.1. The Quarter Hour RR Cashflow is the total cashflow resulting from a RR Activations from BM Unit i in Quarter Hour J.
Quarter Hour Volume GB Need Met	VGB^J	MWh	For each Quarter Hour, data derived from Quarter Hour Interconnector Schedule pursuant to Annex T1 paragraph 1.2.(b).vii or paragraph 1.2.(c).vii
Quarter Hour Volume Interconnector Schedule	VI^J	MWh	For each Quarter Hour, data derived from Quarter Hour Interconnector Schedule pursuant to Annex T1 paragraph 1.2.(b).viii or paragraph 1.2.(c).viii
Ranked Set			Has the meaning given to that term in paragraph 1.2 of Annex T-1.
Registered Capacity		MW	Has the meaning given to that term in the Grid Code.
Remaining Period BM Unit Non-Delivered Bid Volume	RQNDB^u_ij	MWh	The quantity determined as such in accordance with Section T4.8.10 The Remaining Period BM Unit Non-Delivered Bid Volume is the amount of Non-Delivered Bid Volume remaining to be allocated to Bid u from BM Unit i in Settlement Period j.
Remaining Period BM Unit Non-Delivered Offer Volume	RQNDO^u_ij	MWh	The quantity determined as such in accordance with Section T4.8.6. The Remaining Period BM Unit Non-Delivered Offer Volume is the amount of Non-Delivered Offer Volume remaining to be allocated to Offer u from BM Unit i in Settlement Period j.
Replacement Buy Price	RBP_j	£/MWh	The Replacement Buy Price determined in accordance with paragraph 15 of Part 2 of Annex T-1.
Replacement Price	RP_j	£/MWh	Means either the Replacement Buy Price or the Replacement Sell Price as determined in accordance with paragraph 15 of Part 2 of Annex T-1, and Replacement Pricing shall have the same meaning.
Replacement Price Average Reference Volume	RPAR		Has the meaning given to that term in Section T1.11.1.
Replacement Reserve Activation Data			Data (comprising the items set out in Section Q5.6.2) to be submitted by the NETSO pursuant to Section Q6.2C.1(d).
Replacement Reserve Activation Price	RRAP_J	£/MWh	The price associated with a Position. Replacement Reserve Activation Price forms part of the Replacement Reserve Activation Data, GB Need Met Data and Interconnector Schedule Data for each Position and is submitted by the NETSO pursuant to Section Q.
Replacement Reserve Activation Time		Spot time	Has the meaning given to that term in Section Q5.6.1.
Replacement Reserve Aggregated Unpriced System Buy Action	RRAUSB_j		In respect of each Quarter Hour within a Replacement Reserve Auction Period, an aggregated unpriced System Buy Action derived from Replacement Reserve Auction Result Data.
Replacement Reserve Aggregated Unpriced System Sell Action	RRAUSS_j		In respect of each Quarter Hour within a Replacement Reserve Auction Period, an aggregated unpriced System Sell Action derived from Replacement Reserve Auction Result Data.
Replacement Reserve Auction Period			A period of 60 minutes in relation to which Replacement Reserve Auction Result Data is associated pursuant to Section Q5.6 and which period corresponds to two complete Settlement Periods with the start of that Replacement Reserve Auction Period coinciding with the Settlement Period that begins on the hour.
Replacement Reserve Auction Period Resolution Type			Indicates the period of time within the Replacement Reserve Auction Period that the associated Replacement Reserve Activation Data, GB Need Met Data and Interconnector Schedule Data relate to. A Replacement Reserve Auction Period Resolution Type may be categorised as PT60 which is comprised of a single period of 60 minutes, PT30 which is comprised of two periods of 30 minutes or PT15 which is comprised of four periods of 15 minutes.
Replacement Reserve Auction Result Data			Data (comprising the items set out in Section Q5.6.1) to be submitted by the NETSO pursuant to Section Q6.2C.1(d).
Replacement Reserve Bid			Has the meaning given to the term TERRE Bid as defined in the Grid Code.
Replacement Reserve Bid Data			In relation to a Replacement Reserve Bid, the data comprising the items set out in the TERRE Data Validation and Consistency Rules (as defined under the Grid Code) to be submitted by the Lead Party of a BM Unit pursuant to Section Q4.3.3 and by the NETSO pursuant to Section Q6.2C.1(d).
Replacement Reserve Bid Price		£/MWh	The price associated with a Replacement Reserve Bid.
Replacement Reserve Instructed Bid Deviation Volume	IBD_ij	MWh	The quantity established in accordance with Section T3.22.2. The Replacement Reserve Bid Deviation Volume is the volume of Bid, in respect of BM Unit i, in Settlement Period j as a result of all acceptances of a Replacement Reserve Bids in that Settlement Period compared to the volume of Bid determined to be the Total Period Deemed Standard Product Bid Volume for that Settlement Period.
Replacement Reserve Instructed Offer Deviation Volume	IOD_ij	MWh	The quantity established in accordance with Section T3.22.1. The Replacement Reserve Offer Deviation Volume is the volume of Offer, in respect of BM Unit i, in Settlement Period j as a result of all acceptances of a Replacement Reserve Offers in that Settlement Period compared to the volume of Offer determined to be the Total Period Deemed Standard Product Offer Volume for that Settlement Period.
Replacement Reserve Period Instructed Bid Deviation Cashflow	CDB_ij	£	The cashflow determined in accordance with T3.23.2.
Replacement Reserve Period Instructed Offer Deviation Cashflow	CDO_ij	£/MWh	The amount determined in accordance with T3.23.1.
Replacement Reserve Period Instruction Deviation Cashflow	CDR_ij	£	The cashflow determined in accordance with T3.24.1.
Replacement Sell Price	RSP_j	£/MWh	The Replacement Sell Price determined in accordance with paragraph 15 of Part 2 of Annex T-1.
Replacement-Priced Ranked Set			The Replacement-priced Ranked Set as provided in paragraph 10.4 of Part 1 of Annex T-1.
Reserve Scarcity Price	RSVP_j	£/MWh	In respect of a Settlement Period, the price determined in accordance with Section T3.13.
Residual Cashflow Reallocation Cashflow	RCRC_aj	£	The cashflow determined in accordance with Section T4.10.3. The Residual Cashflow Reallocation Cashflow is the cashflow to Energy Account a in Settlement Period j resulting from the reallocation the Total System Residual Cashflow.
Residual Cashflow Reallocation Proportion	RCRP_aj		The proportion determined in accordance with Section T4.10.2. The Residual Cashflow Reallocation Proportion is a fraction expressing the proportion of the Total System Residual Cashflow to be allocated to Energy Account a in Settlement Period j.
RR Schedule			A MW profile constructed by the SAA that provides a baseline for RR Activations with ramping considerations. This MW profile is processed by Settlement in the same way as Bid-Offer Acceptance but not settled under Bid-Offer Prices.
Run-Down Rate(s)			Has the meaning given to that term in BC1 of the Grid Code.
Run-Up Rate(s)			Has the meaning given to that term in BC1 of the Grid Code.
Secondary BM Unit AMSID Pair Data			Has the meaning given to that term in Section S paragraph 10.1A
Secondary BM Unit Delivered Volume	QVBMD_i2NKji	MWh	The quantity determined in accordance with 7.1.1D Annex S-2.
Secondary BM Unit Supplier Delivered Volume	VBMUSDV_i2ji	MWh	The Secondary BM Unit half hourly Supplier Delivered Volumes determined by the SVAA pursuant to paragraph 9.6.1C of Annex S-2.
Second-Stage Flagged			Second-Stage Flagged in accordance with paragraph 8 of Part 1 of Annex T-1.
Sell Price Price Adjustment	SPAj	£/MWh	The amount sent by the NETSO as the ‘Sell Price Price Adjustment’ in accordance with Section Q6.3.
Settlement Period	j		A period of 30 minutes beginning on the hour or the half-hour and in accordance with paragraph 4.3 of this Annex X-2.
Settlement Period Duration	SPD	Hours	0.5 hours.
Site Specific Line Loss Factor			A Line Loss Factor established for a single Metering System as provided in Section K1.7.2.
Small Scale Third Party Generating Plant Limit	SSTPGPL		The quantity established in accordance with Section L1.5 The Small Scale Third Party Generating Plant Limit is the maximum generation capacity (measured at the Boundary Point) of the aggregate Small Scale Third Party Generating Plant connected to a Distribution System at a single Boundary Point.
SO-Flagged Ranked Set			One of the SO-Flagged Ranked Sets as provided in paragraph 4 of Part 1 of Annex T-1.
Stable Export Limit			Has the meaning given to that term in BC1 of the Grid Code.
Stable Import Limit			Has the meaning given to that term in BC1 of the Grid Code.
Start Point Demand Control Level		MW	Has the meaning given to that term in Section T3.15(a)(a).
STOR Action			An Accepted Offer derived from a STOR Flagged BOA taken by the NETSO during a STOR Availability Window in order to increase generation or reduce demand.
STOR Action Price	STAP^t_j	£/MWh	In relation to each STOR Action, the price determined in accordance with Section T3.14
STOR Instructed Volume	QSIV^t_j	MWh	The Period Accepted Offer Volume in respect of each STOR Action instructed by the NETSO in order to increase generation or reduce demand.
Submitted Bid-Offer Pair			A Bid-Offer Pair in respect of which the NETSO submits Bid-Offer Data pursuant to Section Q6.2.
Supplier BM Unit Non BM ABSVD	SNBABSVD_ij	MWh	The amount determined by the SVAA pursuant to Annex S-2 paragraph 9.6.1C.
Surplus	SPLD or SPLW	MW	Has the meaning given to that term in OC2 of the Grid Code
SVA (Production) Funding Share	FSPS_pm		Has the meaning given to that term in Section D1.2.1(c). In relation to a month m, the SVA (Production) Funding Share represents a Party’s proportionate share of aggregate Credited Energy Volumes for Production BM Units for that month.
System Action	w		Has the meaning given to that term in paragraph 1.2 of Annex T-1.
System Action Price	SAP^w_j	£/MWh	Has the meaning given to that term in paragraph 1.2 of Annex T-1.
System Buy Action	QSB^w_j	MWh	Has the meaning given to that term in paragraph 1.2 of Annex T-1.
System Buy Price	SBP_j	£/MWh	The price determined in accordance with Section T4.4.2.
System Demand Control Volume	QSDC_cj	MWh	Has the meaning given to it in Section T3.15.3(a).
System Operator Cashflow	CSO_j	£	The amount determined in accordance with Section T4.9.1. The System Operator Cashflow is the amount paid by or to the System Operator in Settlement Period j in relation to the settlement of the Balancing Services.
System Sell Action	QSS^w_j	MWh	Has the meaning given to that term in paragraph 1.2 of Annex T-1.
System Sell Price	SSP_j	£/MWh	The price determined in accordance with Section T4.4.3.
System Warning			Has the meaning given to that term in BC1 of the Grid Code.
System Zone			Has the meaning given to that term in the Grid Code.
Total Instantaneous Out-Turn Generation		MW	The total instantaneous generation metered by the NETSO in accordance with CC6.5.6 of the Grid Code.
Total Metered Capacity		MW	The total value of the Registered Capacity of all Power Park Modules metered by the NETSO in accordance with CC6.5.6 of the Grid Code.
Total Output Usable		MW	Means the sum of Output Usables (as defined in the Grid Code) excluding (unless expressly stated otherwise in the Code) expected Interconnector transfer capacity.
Total Period Applicable Balancing Services Volume	TQAS_j	MWh	The amount determined in accordance with Section T4.6.5. The Total Period Applicable Balancing Services Volume is the net quantity of energy associated with delivery of Applicable Balancing Services by all BM Units in Settlement Period j.
Total Period Deemed Standard Product Bid Volume	TDSPB_ij	MWh	The quantity established in accordance with Section T3.21.2. The Total Period Deemed Standard Product Bid Volume is the volume of Bid, accepted in respect of BM Unit i, in Settlement Period j as a result of all acceptances of a Replacement Reserve Bid in that Settlement Period.
Total Period Deemed Standard Product Offer Volume	TDSPO_ij	MWh	The quantity established in accordance with Section T3.21.1. The Total Period Deemed Standard Product Offer Volume is the volume of Offer, accepted in respect of BM Unit i, in Settlement Period j as a result of all acceptances of a Replacement Reserve Bid in that Settlement Period.
Total Period Out-Turn Generation		MW	In respect of a Settlement Period, the total generation for that Settlement Period as metered by the NETSO in accordance with CC6.5.6 of the Grid Code.
Total Specified BSC Charges	TSC_pm	£	The sum of the Specified BSC Charges for Trading Party p relating to month m.
Total System Cashflow	TCBM_j	£	The amount determined in accordance with Section T3.12.1. The Total System Cashflow is the total payments and charges in respect of settlement of Balancing Services action for all BM Units, disregarding any Non-Delivered Offer Charges and Non-Delivered Bid Charges.
Total System Energy Imbalance Cashflow	TCEI_j	£	The amount determined in accordance with Section T4.7.2. The Total System Energy Imbalance Cashflow is the total cashflow resulting from the Settlement of Energy Imbalances, summed over all Energy Accounts in Settlement Period j.
Total System Energy Imbalance Volume	TQEI_j	MWh	The quantity determined in accordance with Section T4.6.4. Total System Energy Imbalance Volume is the sum over all Energy Accounts of the Account Energy Imbalance Volume..
Total System Information Imbalance Charge	TCII_j	£	The amount determined in accordance with Section T4.3.7. The Total System Information Imbalance Charge is the total charge for information imbalances, summed over all BM Units in Settlement Period j.
Total System Non-Delivery Charge	TCND_j	£	The amount determined in accordance with Section T4.8.14. The Total System Non-Delivery Charge is the BM Unit Period Non-Delivery Charge summed over all BM Units in Settlement Period j.
Total System Residual Cashflow	TRC_j	£	The amount determined in accordance with Section T4.10.1. The Total System Residual Cashflow is the surplus or deficit of funds remaining to be reallocated after the Settlement of Energy Imbalances, Information Imbalances, the Balancing Mechanism (including non-delivery) and the System Operator BM Charge.
Total System RR Cashflow	TCRR_j	£	The amount determined in accordance with Section T3.25.1. The Total System RR Cashflow is the summation of Quarter Hour RR Cashflow (CRR_iJ) across all BM Units i and across both Quarter Hours J falling within a given Settlement Period j.
Trading Unit Delivery Mode			A flag identifying whether a Trading Unit was a delivering Trading Unit or an offtaking Trading Unit determined in accordance with Section T6.1.3.
Trading Unit Export Volume	QTUE_rj	MWh	The volume determined in accordance with Section T6.1.1.
Trading Unit Import Volume	QTUI_rj	MWh	The volume determined in accordance with Section T6.1.2.
Transmission Energy		MWh	The integral with respect to time of National Demand.
Transmission Loss Factor	TLF_ij		The factor specified in Section T2.2.1(a). The Transmission Loss Factor is that factor used to allocate transmission losses on a locational basis to BM Unit i in Settlement Period j.
Transmission Loss Factor Adjustment	TLFA_S		The value determined in accordance with paragraph 9.1 of Annex T-2. The Transmission Loss Factor Adjustment is the value calculated to ensure that, as far as possible, the Adjusted Seasonal Zonal TLF (ATLF_ZS) values have a zero net aggregate effect on Delivering Transmission Losses Adjustment (TLMO⁺_j) values.
Transmission Loss Multiplier	TLM_ij		The multiplier calculated in accordance with Section T2.3.1(a) or (b). The Transmission Loss Multiplier is the factor applied to BM Unit i in Settlement Period j in order to adjust for Transmission Losses.
Transmission System Demand			Has the meaning given to the term National Electricity Transmission System Demand as defined in the Grid Code.
Transmission System Frequency		Hertz	The Frequency of the Transmission System.
Unsubmitted Bid-Offer Pair			Has the meaning given to that term in Section T3.4B.2.
Utilisation Price		£/MWh	The amount sent by the NETSO as a utilisation payment in respect of a STOR Action which: (i) in relation to a BM STOR Action shall be the Offer Price; and (ii) in relation to a Non-BM STOR Action shall be the Balancing Services Adjustment Cost.
Value of Lost Load	VoLL	£/MWh	Has the meaning given to it in Section T1.12.1.
Working Day Credit Assessment Load Factor	WDCALFi		Is defined in Annex X-1. The factor is used to establish the BM Unit Credit Assessment Export Capability and BM Unit Credit Assessment Import Capability for BM Uniti on a CALF Working Day determined for the purposes of Credit Assessment Load Factor.
Zonal Transmission System Demand			The forecast quantity of Transmission System Demand in a BMRS Zone.

Table X-3 - Glossary of Acronyms Applying Except In Relation To Section S

This table provides a list of the acronyms defined in Table X-2, presented in alphabetical order of the acronym name.

Acronym	Units	Corresponding Defined Term or Expression
AEI_p	MWh	Actual Energy Indebtedness
BEDP_j	£/MWh	Balancing Energy Deviation Price
BMCAEC_i	MW	BM Unit Credit Assessment Export Capability
BMCAIC_i	MW	BM Unit Credit Assessment Import Capability
BMUADDV_ij	MWh	BM Unit Allocated Demand Disconnection Volume
BMUADV_ij	MWh	BM Unit Allocated Demand Volume
BOLRⁿ_ij(t)	MW	Bid-Offer Lower Range
BOURⁿ_ij(t)	MW	Bid-Offer Upper Range
BPA_j	£/MWh	Buy Price Price Adjustment
BSAP^m_j	£/MWh	Balancing Services Adjustment Price
CAD^k_i	Minutes	Continuous Acceptance Duration
CADL	Minutes	Continuous Acceptance Duration Limit
CAEI_aj	£	Account Energy Imbalance Cashflow
CAEI_p	£	Daily Party Energy Imbalance Cashflow
CALF_i		Credit Assessment Load Factor
CAP	£/MWh	Credit Assessment Price
CAQCE_iaj	MWh	Credit Assessment Credited Energy Volume
CBM_ij	£	Period BM Unit Cashflow
CBM_p	£	Daily Party BM Unit Cashflow
CBⁿ_ij	£	Period BM Unit Bid Cashflow
CCEC_p	£	Credit Cover Error Compensation
CC_p	£	Credit Cover
CCP_pj	%	Credit Cover Percentage
CCR_iJ		Quarter Hour RR Cashflow
CDB_ij	£	Replacement Reserve Period Instructed Bid Deviation Cashflow
CDO_ij	£/MWh	Replacement Reserve Period Instructed Offer Deviation Cashflow
CDR_ij	£	Replacement Reserve Period Instruction Deviation Cashflow
CDR_p	£	Daily Party RR Instruction Deviation Cashflow
CEI_pj	MWh	Credit Assessment Energy Indebtedness
CGCAEI_aj	£	Claim Group non-corrected Account Energy Imbalance Cashflow
CII_ij	£	Information Imbalance Charge
CII_p	£	Daily Party Information Imbalance Charge
CNDBⁿ_ij	£	Non-Delivered Bid Charge
CND_ij	£	BM Unit Period Non-Delivery Charge
CNDOⁿ_ij	£	Non-Delivered Offer Charge
CND_p	£	Daily Party Non-Delivery Charge
COⁿ_ij	£	Period BM Unit Offer Cashflow
CORC_iNj	MWh	Corrected Component
CORABSVDC_i2Nj		Corrected MSID ABSVD Component
CRR_ij	£	Period RR BM Unit Cashflow
CRR_p	£	Daily Party RR Cashflow
CSO	£	Daily System Operator BM Cashflow
CSO_j	£	System Operator BM Cashflow
DMAT	MWh	De Minimis Acceptance Threshold
DSPB^J_ij	MWh	Period Deemed Standard Product Bid Volume
DSPO^J_ij	MWh	Period Deemed Standard Product Offer Volume
ECA_pj	£	Credit Cover Error Interest Amount
ECB_pj	£	Credit Cover Error Imbalance Amount
ECC_p	MWh	Energy Credit Cover
ECQ_zabj	MWh	Energy Contract Volume
EEI_pj	MWh	Erroneous Energy Indebtedness
EI_pj	MWh	Energy Indebtedness
f		Point Value Identification Number
^fFPN_ijt	MW	Point FPN
FLAG_pj		Credit Cover Error Erroneous Rejection Flag
FPN_ij	MWh	Period FPN
FPN_ij(t)	MW	FPN
^fqBOⁿ_ijt	MW	Point Bid-Offer Volume
FSG_pm		General Funding Share
FSM_pm		Main Funding Share
FSPS_pm		SVA (Production) Funding Share
i		BM Unit Identification Number
IBD_ij	MWh	Replacement Reserve Instructed Bid Deviation Volume
ICBⁿ_ij	£	Indicative Period Balancing Mechanism Bid Cashflow
ICOⁿ_ij	£	Indicative Period Balancing Mechanism Offer Cashflow
IECC_p	MWh	Initial Energy Credit Cover
IIP_j	£/MWh	Information Imbalance Price
IMBALNGC	MW	Indicated Imbalance
IMV_j	MWh	Interconnector Metered Volume
INDDEM	MW	Indicated Demand
INDGEN	MW	Indicated Generation
INDO	MW	Initial National Demand Out-Turn
INIV_j	MWh	Indicative Net Imbalance Volume
IOD_ij	MWh	Replacement Reserve Instructed Offer Deviation Volume
IQABⁿ_ij	MWh	Indicative Period BM Unit Total Accepted Bid Volume
IQAOⁿ_ij	MWh	Indicative Period BM Unit Total Accepted Offer Volume
ISBP_j	£/MWh	Indicative System Buy Price
ISSP_j	£/MWh	Indicative System Sell Price
ITSDO	MW	Initial Transmission System Demand Out-Turn
j		Settlement Period
k		Bid-Offer Acceptance Number
LLFC		Line Loss Factor Class
LoLP_j		Final Loss of Load Probability
m		Balancing Services Adjustment Action
MAQCE_iaj	MWh	Metered Credit Assessment Credited Energy Volume
MDC_m	£	Monthly Default Costs
MEI_pj	MWh	Metered Energy Indebtedness
MELNGC	MW	Indicated Constraint Boundary Margin
MNMC_m	£	Monthly Net Main Costs
MPDV	MWh	MSID Pair Delivered Volume
MP_j		Market Price
MPSC_m	£	Monthly Production-Charging SVA Costs
n		Bid-Offer Pair Number
NDPBⁿ_ij	£/MWh	Non-Delivered Bid Price
NDPOⁿ_ij	£/MWh	Non-Delivered Offer Price
NIV_j	MWh	Net Imbalance Volume
NTEBVA_j	MWh	NIV Tagged EBVA
NTESVA_j	MWh	NIV Tagged ESVA
NUEBVA_j	MWh	NIV Untagged EBVA
NUESVA_j	MWh	NIV Untagged ESVA
NWDCALF_i		Non-Working Day Credit Assessment Load Factor
OCNMFD	MW	Generating Plant Demand Margin (daily value)
OCNMFW	MW	Generating Plant Demand Margin (weekly value)
PAR	MWh	Price Average Reference Volume
PBⁿ_ij	£/MWh	Bid Price
POⁿ_ij	£/MWh	Offer Price
PXP_sj	£/MWh	Market Index Price
QABC_aj	MWh	Account Bilateral Contract Volume
QAB^kn_ij	MWh	Period Accepted Bid Volume
qAB^kn_ij(t)	MW	Accepted Bid Volume
QABⁿ_ij	MWh	Period BM Unit Total Accepted Bid Volume
qABO^kn_ij(t)	MW	Accepted Bid-Offer Volume
QABS_aj	MWh	Account Period Balancing Services Volume
QACE_aj	MWh	Account Credited Energy Volume
QAEI_aj	MWh	Account Energy Imbalance Volume
qA^k_ij(t)	MW	Acceptance Volume
qA^k_it	MW	Point Acceptance Volume
QAO^kn_ij	MWh	Period Accepted Offer Volume
qAO^kn_ij(t)	MW	Accepted Offer Volume
QAOⁿ_ij	MWh	Period BM Unit Total Accepted Offer Volume
QAS_ij	MWh	BM Unit Applicable Balancing Services Volume Data or BM Unit ABSVD
QBDC_cj	MWh	Balancing Demand Control Volume
qBOⁿ_ij(t)	MW	Bid-Offer Volume
QBSAB^m_j	MWh	Balancing Services Adjustment Buy Volume
QBSA^m_j	MWh	Balancing Services Adjustment Volume
QBSAS^m_j	MWh	Balancing Services Adjustment Sell Volume
QBSD_ij	MWh	Period Supplier BM Unit Delivered Volume
QBS_ij	MWh	Period BM Unit Balancing Services Volume
QCE_iaj	MWh	Credited Energy Volume
QDD_ij	MWh	Period BM Unit Demand Disconnection Volume
qDSPB^J_ij(t)	MW	Deemed Standard Product Bid Volume
qDSP^J_ij(t)	MW	Deemed Standard Product Shape
qDSP^J_ijt	MW	Deemed Standard Product Point Variables
qDSPO^J_ij(t)	MW	Deemed Standard Product Offer Volume
qDSPV^J_ij(t)	MW	Deemed Standard Product Volume
QII_ij	MWh	Period Information Imbalance Volume
QME_ij	MWh	Period Expected Metered Volume
QMFR_iaj	MWh	Metered Volume Fixed Reallocation
QMFR_ziaj	MWh	Metered Volume Reallocation Fixed Data
QM_ij	MWh	BM Unit Metered Volume
QMPR_iaj	%	Metered Volume Percentage Reallocation
QMPR_ziaj	%	Metered Volume Reallocation Percentage Data
QNDB_ij	MWh	Period BM Unit Non-Delivered Bid Volume
QNDBⁿ_ij	MWh	Bid Non-Delivery Volume
QNDO_ij	MWh	Period BM Unit Non-Delivered Offer Volume
QNDOⁿ_ij	MWh	Offer Non-Delivery Volume
QSB^w_j		System Buy Action
QSDC_cj	MWh	System Demand Control Volume
QSD_{ij or}QSD_i2j	MWh	Period Secondary BM Unit Delivered Volume
QSD_iji2	MWh	Period Secondary BM Unit Supplier Delivered Volume
QSIV^t_j	MWh	STOR Instructed Volume
QSND_ij	MWh	Period Secondary BM Unit Non-Delivered Volume
QSS^w_j		System Sell Action
QTUE_rj	MWh	Trading Unit Export Volume
QTUI_rj	MWh	Trading Unit Import Volume
QVBMD_i2NKij	MWh	Secondary BM Unit Delivered Volume
QXP_sj	MWh	Market Index Volume
RBP_j	£/MWh	Replacement Buy Price
RCRC_aj	£	Residual Cashflow Reallocation Cashflow
RCRC_p	£	Daily Party Residual Settlement Cashflow
RCRP_aj	No Units	Residual Cashflow Reallocation Proportion
REJ_aj	MWh	Credit Cover Error Rejection Volume
RPAR		Replacement Price Average Reference Volume
RP_j	£/MWh	Replacement Price
RQNDB^u_ij	MWh	Remaining Period BM Unit Non-Delivered Bid Volume
RQNDO^u_ij	MWh	Remaining Period BM Unit Non-Delivered Offer Volume
RRAB^kn_ij	MWh	Period RR Accepted Bid Volume
RRABⁿ_ij	MWh	Period RR Total Accepted Bid Volume
RRAO^kn_ij	MWh	Period RR Accepted Offer Volume
RRAOⁿ_ij	MWh	Period RR Total Accepted Offer Volume
RRAP_J	£/MWh	Replacement Reserve Activation Price
RRAUSB_j		Replacement Reserve Aggregated Unpriced System Buy Action
RRAUSS_j		Replacement Reserve Aggregated Unpriced System Sell Action
RRAV_iJ	MWh	Quarter Hour RR Activated Volume
RSP_j	£/MWh	Replacement Sell Price
RSVP_j	£/MWh	Reserve Scarcity Price
SAP^w_j		System Action Price
SBP_j	£/MWh	System Buy Price
SNBABSVD_ij	MWh	Supplier BM Unit Non BM ABSVD
SPA_j	£/MWh	Sell Price Price Adjustment
SPBMEI_aij	MWh	Settlement Period BM Unit Energy Indebtedness
SPD	h	Settlement Period Duration
SP_iji2	MWh	Period Secondary BM Unit Delivered Proportion
SPLD	MW	Surplus (daily value)
SPLW	MW	Surplus (weekly value)
SSP_j	£/MWh	System Sell Price
SSTPGPL		Small Scale Third Party Generating Plant Limit
STAP^t_j	£/MWh	STOR Action Price
TCBM_j	£	Total System BM Cashflow
TCEI_j	£	Total System Energy Imbalance Cashflow
TCII_j	£	Total System Information Imbalance Charge
TCND_j	£	Total System Non-Delivery Charge
TCRR_j	£	Total System RR Cashflow
TDSPB_ij	MWh	Total Period Deemed Standard Product Bid Volume
TDSPO_ij	MWh	Total Period Deemed Standard Product Offer Volume
T^k_it	Spot time	Bid-Offer Acceptance Time
TLFA_S		Transmission Loss Factor Adjustment
TLF_ij		Transmission Loss Factor
TLM_ij	No Units	Transmission Loss Multiplier
TLMO⁺_j		Delivering Transmission Losses Adjustment.
TLMO^-_j		Offtaking Transmission Losses Adjustment
TQAS_j	MWh	Total Period Applicable Balancing Services Volume
TQEI_j	MWh	Total System Energy Imbalance Volume
TRC_j	£	Total System Residual Cashflow
TSC_pm	£	Total Specified BSC Charges
u		Non-Delivery Order Number
VBMUSDV_i2ij	MWh	Secondary BM Unit Supplier Delivered Volume
VoLL	£/MWh	Value of Lost Load
w		System Action
WDCALF_i		Working Day Credit Assessment Load Factor

Table X–4 - Use of Subscripts and Superscripts Applying to Section S

The following subscripts used in the formulae and other algebraic expressions contained in the Code shall bear the following respective meanings for Section S of the Code:

a	refers to a Data Aggregator or, as the context may require in paragraph 3.5 of Annex S-2, to a Data Aggregator appointed by a Primary Supplier against a Primary SVA Metering System Number and a Data Aggregator appointed by an associated Secondary Supplier against a Secondary SVA Metering System Number;
a1	refers to a Data Aggregator appointed by a Primary Supplier against a Primary SVA Metering System Number K1;
a1.1	refers to a Data Aggregator appointed by a Primary Supplier against a Primary SVA Metering System Number K1.1;
an	refers to a Data Aggregator appointed by a Secondary Supplier against a Secondary SVA Metering System Number Kn;
an.1	refers to a Data Aggregator appointed by a Secondary Supplier against a Secondary SVA Metering System Number Kn.1;
(aa)	refers to an Analysis Class;
(ai)	refers to an Adjusted Interval;
j	refers to a Settlement Period;
i	refers to a BM Unit;
i2	refers to a Secondary BM Unit (where applicable);
(nn)	refers to an individual value of the Regression Coefficient (RC) or of the Matrix of Regression Coefficients (MRC), according to the context;
(vv)	refers to a Consumption Component Class (not for line losses) associated with Consumption Component Class N;
(vvn)	refers to a Consumption Component Class (not for line losses) associated with Consumption Component Class N for which the data aggregation type is ‘N’;
q	refers to a calendar quarter;
d(q)	refers to the number of days in a calendar quarter;
C	refers to a Standard Settlement Configuration;
G	refers to a Supplier Volume Reporting Group;
H	refers to a GSP Group;
J	refers to a Settlement Register;
K	Refers to a Metering System associated with an SVA Storage Facility; and refers to an SVA Metering System Number and/or Asset Metering System associated with the provision of a Balancing Service;
K1	refers to a Primary SVA Metering System Number;
K1.1	refers to the "virtual" Primary SVA Metering System Number where Section K2.5.4(c)(ii) applies to the Primary Supplier;
Kn	refers to a Secondary SVA Metering System Number;
Kn.1	refers to the "virtual" Secondary SVA Metering System Number where Section K2.5.4(c)(ii) applies to the Secondary Supplier;
L	refers to a Line Loss Factor Class;
N	refers to a Consumption Component Class;
N(c)	refers to a non half hourly active import Consumption Component Class;
P	refers to a Profile Class;
Q	refers to a Profile;
R	refers to a valid combination of Time Pattern Regime and Standard Settlement Configuration;
T	refers to a Settlement Day;
X	refers to a Time Pattern Regime;
Y	refers to a calendar year;
Z	refers to a Supplier or, as the context may require in paragraph 3.5 of Annex S-2, to the Suppliers acting in the capacity of Primary Supplier and associated Secondary Supplier(s) in respect of a particular Shared SVA Metering System;
Z1	refers to a Supplier acting in the capacity of Primary Supplier in respect of a Shared SVA Metering System; and
Zn	refers to a Supplier acting in the capacity of Secondary Supplier in respect of a Shared SVA Metering System.

Table X–5 - Use of Summations Applying to Section S

The following summations, used in the formulae and other algebraic expressions in Section S, shall bear the following respective meanings:

Σ_a	=	summed over all Data Aggregators (a);
Σ_(ai)	=	summed over all Adjusted Intervals ((ai)) associated with the spot time in question for all Time Pattern Regimes associated with a particular Standard Settlement Configuration;
Σ_j	=	summed over all Settlement Periods;
Σ_N	=	summed over all Consumption Component Classes (N) where, in such summation, values associated with Consumption Component Classes associated with Third Party Generating Plant comprised in SVA Metering Systems shall be subtracted and values associated with all other Consumption Component Classes shall be added, except in the case of Σ_N(AA) and Σ_N(EAC)for the purposes of Annex S-1 paragraph 2;
Σ_N(n)	=	summed over all those Consumption Component Classes (N) for which the data aggregation type is ‘N’ and where, in such summation, values associated with Consumption Component Classes associated with Third Party Generating Plant comprised in SVA Metering Systems shall be subtracted and values associated with all other Consumption Component Classes shall be added;
Σ_T	=	summed over all Settlement Days (T) in a particular Meter Advance Period;
Σ_Z	=	summed over all Suppliers (Z);
Σ^K_J	=	summed over all Settlement Registers (J) in a particular SVA Metering System (K);
Σ^NL_K	=	summed over all SVA Metering Systems (K) within a particular Line Loss Factor Class (L) and Consumption Component Class (not for line losses) (N);
Σ^(vv)L_K	=	summed over all SVA Metering Systems (K) within a Line Loss Factor Class (L) and Consumption Component Class (for line losses) associated with a particular Consumption Component Class (not for line losses) ((vv));
Σ^(vv)_LK	=	summed over all Line Loss Factor Classes (L) and Metering Systems K within a Consumption Component Class (for losses) associated with a particular Consumption Component Class (not for losses) ((vv));
Σ^N_LPR	=	summed over all kWh readings within a Settlement Class (LPR) itself within a particular Consumption Component Class (N);
Σ^N(n)_LPR	=	summed over all kWh readings within a Settlement Class (LPR) itself within a particular Consumption Component Class (N) for which the data aggregation type is ‘N’;
Σ^(vv)_L	=	summed over all Line Loss Factor Classes (L) within a Consumption Component Class (for losses) associated with a particular Consumption Component Class (not for losses) ((vv));
Σ^(vvn)_L	=	summed over all Line Loss Factor Classes (L) within a Consumption Component Class (for losses) associated with a particular Consumption Component Class (not for line losses) for which the data aggregation type is ‘N’ ((vvn));
Σ^(vv)_PR	=	summed over all Profile Classes (P) and Time Pattern Regimes within Standard Settlement Configuration (R) within a Consumption Component Class (for losses) associated with a particular Consumption Component Class (not for losses) ((vv));
Σ^(vvn)_PR	=	summed over all Profile Classes (P) and Time Pattern Regimes within Standard Settlement Configuration (R) within a Consumption Component Class (for losses) associated with a particular Consumption Component Class (not for line losses) for which the data aggregation type is ‘N’ ((vvn));
Σ^HZLPR_K	=	summed over all non half hourly SVA Metering Systems (K) by Settlement Class (HLPR) for a particular Supplier (Z); and
Σ^H_Z	=	summed over all Suppliers (Z) active within a particular GSP Group (H).
Σ_ON	=	summed over all Settlement Periods in a Settlement Day for which the Modified Switched Load State Indicator (SQNEW_Cj) has been determined as equal to one by the Supplier Volume Allocation Agent;
Σ_OFF	=	summed over all Settlement Periods in a Settlement Day for which the Modified Switched Load State Indicator (SQNEW_Cj) has been determined as equal to zero by the Supplier Volume Allocation Agent;
Σ_N(AA)	=	summed over all Consumption Component Classes N that are associated with Annualised Advances;
Σ_N(EAC)	=	summed over all Consumption Component Classes N that are associated with Estimated Annual Consumptions;
Σ^m_d	=	summed over all Settlement Days in a month
Σ_N(HHA)	=	summed over all Consumption Component Classes that are associated with actual values and with half hourly data aggregation in relation to Metering Systems which are 100kW Metering Systems save those which are associated with SVA Generation and SVA Generation line losses;
Σ_N(HHE)	=	summed over all Consumption Component Classes that are associated with estimated values and with half hourly data aggregation in relation to Metering Systems which are 100kW Metering Systems save those which are associated with SVA Generation and SVA Generation line losses.
Σ^H_i	=	summed over all Supplier BM Units (i) associated with a particular GSP Group (H);
Σ^HZ_i	=	summed over all Supplier BM Units (i) associated with a particular GSP Group (H) and Supplier (Z);
Σ^HPR_ZL	=	summed over all Suppliers (Z) and Line Loss Factor Classes (L) for Standard Settlement Configuration and Time Pattern Regime combination (R) in Profile Class (P) within GSP Group (H);
Σ^HPR_T	=	summed over all Settlement Days (T) contained within the Calculation Period for which one or more values of TAA_HZLPR was determined for Standard Settlement Configuration and Time Pattern Regime combination (R) in Profile Class (P) within GSP Group (H);
Σ^HPC_R	=	summed over all Standard Settlement Configuration and Time Pattern Regime combinations (R) valid for Standard Configuration (C) and Profile Class (P) within GSP Group (H);
Σ^HPCT_R	=	summed over all Standard Settlement Configuration and Time Pattern Regime combinations (R) valid for Standard Settlement Configuration (C) in Profile Class (P) within GSP Group (H) for Settlement Day (T);
Σ^HPC_ZL	=	summed over all Suppliers (Z) and Line Loss Factor Classes (L) for any one valid combination of Standard Settlement Configuration and Time Pattern Regime for Standard Settlement Configuration (C) in Profile Class (P) within GSP Group (H);
Σ^HPT_C	=	summed over all Standard Settlement Configurations (C) for Profile Class (P) within GSP Group (H) for Settlement Day (T);
Σ^HP_T	=	summed over all Settlement Days (T) for Profile Class (P) within GSP Group (H).
Σ_N(AI)	=	summed over all Consumption Component Classes N that are associated with active import.
Σ^ZqG	=	summed by Supplier (Z) over a calendar quarter (q) by Supplier Volume Reporting Group (G);

Table X–6 - Definitions Applying To Section S

Unless otherwise expressly stated the expressions below bear the following meanings in Section S.

The definition of Non Half Hourly Supplier Deemed Take (NHHSDT_HZj) also applies to Annex D-1. The definition of Measurement Class also applies to Section W.

Expression	Acronym	Units	Definition
	K1_HPC and K2_HPC	Numbers	Baseload Profile Consumption during the ‘on’ and ‘off’ periods respectively of switched load Time Pattern Regimes for a valid Standard Settlement Configuration associated with switched load, determined pursuant to paragraph 6.6 of Annex S-2.
	SIX_PM	Minutes	The time duration from the start of the Settlement Day to 1800 hours Greenwich Mean Time on that Settlement Day, determined pursuant to paragraph 6.5 of Annex S-2.
ABSVD BM Unit Delivered Volume	AQVMD_NLKji	MWh	The quantity determined in accordance with paragraph 7.1.1E of Annex S-2.
Adjusted Interval			A period of time associated with a particular Time Pattern Regime based on a time period for which the associated Settlement Registers record Metered Data and determined pursuant to paragraph 6.4 of Annex S-2.
Adjusted Interval End Time			A time associated with a particular Time Pattern Regime and Standard Settlement Configuration determined pursuant to paragraph 6.4 of Annex S-2.
Adjusted Interval Start Time			A time associated with a particular Time Pattern Regime and Standard Settlement Configuration determined pursuant to paragraph 6.4 of Annex S-2.
Allocated BM Unit’s Demand Disconnection Volume	ABDD_iaNLKj	kWh	The half hour Demand Disconnection volume of a Metering System determined pursuant to paragraph 3.8 of Annex S-2.
Allocated BM Unit’s Metering System Metered Consumption	ABMMMC_iaNLKj	kWh	The half hour metered Consumption of a Metering System determined pursuant to paragraph 3.6 of Annex S-2.
Allocated Metering System Metered Consumption	AVMMC_HZaNLKji	MWh	The quantity determined in accordance with paragraph 3.9.2 of Annex S-2. The Allocated Metering System Metered Consumption is the Half Hourly metered volume per Settlement Period of SVA Metering Systems
Allocated Asset Metering System Metered Consumption	AAVMMC_HNLKj	kWh	The quantity determined in accordance with paragraph 3.9.2A of Annex S-2. The Allocated Asset Metering System Metered Consumption is the Half Hourly metered volume per Settlement Period of Asset Metering Systems
Asset Metering System Metered Consumption	AMMC_Kj	kWh	The half hourly metered Consumption for a SVA Metering System, determined pursuant to paragraph 3.5 of Annex S-2.
Asset Metering System Metered Consumption	VMMC_HNLKj	MWhkWh	The Metering System Metered Consumption for an Asset Metering System, determined pursuant to paragraph 7.1.1C of Annex S-2.
Allocated Supplier’s Demand Disconnection Volume	ASDD_HZaNLKj	kWh	The half hour Demand Disconnection volume of a SVA Metering System determined pursuant to paragraph 3.7 of Annex S-2.
Allocated Supplier’s Metering System Metered Consumption	ASMMC_HZaNLKj	kWh	The half hour metered Consumption of a SVA Metering System determined pursuant to paragraph 3.5 of Annex S-2.
AMSID Pair Data			The data comprising the data items pursuant to Section S10.1A
AMSID Pair Delivered Volume	AMPDV_j	MWh	AMSID Pair Delivered Volume is such volumes of Active Energy notified by the Virtual Lead Party in relation to an AMSID Pair and each Associated MSID Pair for the purposes of aggregating Secondary BM Unit Supplier Delivered Volume (VBMUSDV_iZj)
Alternative Average Fraction of Yearly Consumption	AAFYC_HPC		A value set from time to time by the Panel for one or more multi‑register Standard Settlement Configurations, and used in place of the corresponding Average Fraction of Yearly Consumption value for the purpose of calculating profile coefficients pursuant to paragraph 5.1 of Annex S-2.
Analysis Class			A combination of Season Type and Day Type.
Annual Fraction of Yearly Consumption Adjustment	AFYCA_HPC		The difference due to rounding between unity and the sum of the Unadjusted Average Fraction of Yearly Consumption Values for a Standard Settlement Configuration and Profile Class within a GSP Group, determined pursuant to paragraph 5.1 of Annex S-2.
Annualised Advance	AA_KR	kWh	An estimation of the Meter Advance on a Settlement Register over a period of a year determined pursuant to paragraph 4.3 of Annex S-2.
Annualised Advance Adjustment Factor	AAAF_KR	Number	A factor used in the determination of Estimated Annual Consumption and determined pursuant to paragraph 4.3 of Annex S-2.
Asset Meter Register Consumption	AMRC_KJj	kWh	The half hourly metered Consumption for a Settlement Register within an Asset Metering System.
Average Fraction Of Yearly Consumption	AFYC_HPR		An estimate of the fraction of the total Consumption of a multi-register Standard Settlement Configuration attributable to each Settlement Register of that Standard Settlement Configuration pursuant to paragraph 4.4 of Annex S-2.
Base Fraction	BF_HPC	Number	The deemed proportion of Consumption for a Switched Load Metering System which is baseload determined pursuant to paragraph 6.6 of Annex S-2.
Baseload Profile			The half-hourly profile of all non-switched loads in the Profile Class population, including non-switched loads taken during the periods when the switched load registers are recording Consumption and referred to in paragraph 6.6 of Annex S-2.
Baseload Profile Coefficient	BAP_HQj	Number	One of the Basic Period Profile Coefficients which correspond to the Baseload Profile associated with a Switched Load Metering System, determined pursuant to paragraph 6.6 of Annex S-2.
Basic Period Profile Coefficient	P_HQj	Number	A number determined pursuant to paragraph 6.5 of Annex S-2 and representing the fraction of annual Consumption in a given Settlement Period for a particular profile.
BM Unit Allocated Demand Disconnection Volume	BMUADDV_ij	MWh	The disconnection volume per Settlement Period for a Supplier BM Unit determined pursuant to paragraph 9.6.1A of Annex S-2.
BM Unit Allocated Demand Volume	BMUADV_ij	MWh	The energy volume per Settlement Period for a Supplier BM Unit determined pursuant to paragraph 9.6.1 of Annex S-2.
BM Unit Disconnection Matrix	BMDM_iaLPR		A matrix of data as determined pursuant to paragraph 8.2 of Annex S-2.
BM Unit Purchase Matrix	BMPM_iaLPR		A matrix of data as determined pursuant to paragraph 8.1 of Annex S-2.
BM Unit’s Demand Disconnection Volume	BMDD_iaNj	MWh	The half hourly Demand Disconnection volume, determined by a Half Hourly Data Aggregator pursuant to paragraph 3.8 of Annex S-2, or by the SVAA pursuant to paragraph 7.1 of Annex S-2.
BM Unit’s Demand Disconnection Volume (Losses)	BMDDL_iaNj	MWh	The line losses determined by a Half Hourly Data Aggregator as resulting from the BM Unit’s Demand Disconnection Volume pursuant to paragraph 3.8 of Annex S-2, or by the SVAA pursuant to paragraph 7.2 of Annex S-2.
BM Unit’s Metered Consumption	BMMC_iaNLj	MWh	The half hourly metered Consumption, determined by a Half Hourly Data Aggregator pursuant to paragraph 3.6 of Annex S-2, or by the SVAA pursuant to paragraph 7.1 of Annex S-2.
BM Unit’s Metered Consumption (Losses)	BMMCL_iaNLj	MWh	The line losses determined by a Half Hourly Data Aggregator as resulting from the BM Unit’s Metered Consumption pursuant to paragraph 3.6 of Annex S-2, or by the SVAA pursuant to paragraph 7.2 of Annex S-2.
BM Unit’s Profiled Consumption	BMPC_iLPRj	MWh	A Supplier BM Unit’s non half hourly Consumption profiled per Settlement Period for a particular Consumption Component Class, determined pursuant to paragraph 8.1 of Annex S-2.
BM Unit’s Profiled Disconnection	BMPD_iLPRj	MWh	A Supplier BM Unit’s non half hourly Demand Disconnection volume profiled per Settlement Period for a particular Consumption Component Class, determined pursuant to paragraph 8.2 of Annex S-2.
Calculation Period			The period of consecutive Settlement Days (typically but not necessarily one year in duration) on whose Supplier Purchase Matrix data the calculation of Average Fractions of Yearly Consumption pursuant to paragraph 5.1 of Annex S-2 is based.
Certificate of Supply			For the purposes of Annex S-2 the Estimated Annual Consumption for a Non Qualifying Unmetered Supply as provided from time to time by Public Distribution Service Operator.
Clock Interval			A combination of seasons, dates, days and times defining the period over which Consumption is recorded by a Settlement Register the details of which are provided pursuant to paragraph 5.1.1 of Annex S-2.
Consumption		MWh	The amount of electricity produced by a SVA Generator or used by an SVA Customer.
Consumption Component Class			A classification of half hourly Consumption and/or electricity produced or used by an Asset which comprises one element from each of the following categories as shown in Table X-8: metered or unmetered; consumption or SVA generation; SVA Metering System with or without Metering System specific line losses (but a SVA Metering System without Metering System specific line losses can only be combined with unmetered Consumption); Consumption without line losses or line losses; based on actual or estimated half hourly; or based on Annualised Advance or Estimated Annual Consumption.
Consumption Data			That part of the Supplier Purchase Matrix containing the values of Total Annualised Advance, Total Metered Estimated Annual Consumption and Total Unmetered Consumption.
Co-ordinated Universal Time	UTC	Number	Bears the same meaning as in the document Standard Frequency and Time Signal Emission, International Telecommunication Union - RTF.460(ISBN92-61-05311-4) (colloquially referred to as Rugby Time).
Corrected Component	CORC_iNj	MWh	The Consumption for a Supplier BM Unit's Consumption Component Class after the application of the GSP Group Correction Factor, determined pursuant paragraph 9.3 of Annex S-2.
Corrected Component by Profile Class	CORC_iN(c)Pj	MWh	The consumption for a Supplier BM Unit's Profile Class after the application of the GSP Group Correction Factor and Line Loss Factor, determined pursuant paragraph 9A.3 of Annex S-2.
Corrected Disconnection Component	CORDC_iNj	MWh	The Demand Disconnection volume for a Supplier BM Unit's Consumption Component Class after the application of the GSP Group Correction Factor, determined pursuant to paragraph 9.3 of Annex S-2.
Corrected MSID ABSVD Component	CORABSVDC_i2Nj	MWh	The quantity determined in accordance with paragraph 9.3.5 of Annex S-2.
Customer Consent Flag			A flag in the SVA Metering System Register indicating that, in relation to a Supplier, an SVA Customer or SVA Generator has consented to their Metering System Delivered Volumes being provided to that Supplier in accordance with paragraphs 7.1.8 and 7.2.8 of Annex S-2.
Daily Profile Coefficient	DPC_HPRT	Number	A value which, when applied to an Estimated Annual Consumption or Annualised Advance value, supplies an estimate of Consumption for a Settlement Day and which is equal to the sum of the corresponding Period Profile Class Coefficients for that Settlement Day.
Day Type			A code describing whether a particular Settlement Day is a weekday, a Saturday, a Sunday, or a particular Bank Holiday.
Deemed Meter Advance	DMA_KR	kWh	An estimated Meter Advance calculated by the relevant Non-Half Hourly Data Collector pursuant to paragraph 4.3 of Annex S-2 and BSCP504.
Deemed Meter Advance Period			A period bearing the same relationship to a Deemed Meter Advance as a Meter Advance Period bears to a Meter Advance.
Default Estimated Annual Consumption For Metered Metering Systems	DEM_HZLPR	kWh	The Estimated Annual Consumption value determined by a Non-Half Hourly Data Aggregator pursuant to paragraph 4.4 of Annex S-2.
Default Estimated Annual Consumption For Unmetered Metering Systems	DEU_HZLPR	kWh	The value of Estimated Annual Consumption determined for an Unmetered Supply pursuant to paragraph 4.4 of Annex S-2.
Demand Disconnection Daily Profile Coefficient	DDDPC_HPKRT	Number	A value which, when applied to an Estimated Annual Consumption or Annualised Advance value, supplies an estimate of Demand Disconnection volume for a Settlement Day and which is equal to the sum of the corresponding Period Profile Class Coefficients for that Settlement Day multiplied by the proportion of each Settlement Period in that Settlement Day for which a given Metering System was subject to Demand Disconnection.
Effective From Settlement Date			The date of the Settlement Day on which an Annualised Advance or an Estimated Annual Consumption becomes effective.
Effective To Settlement Date			The date of the last Settlement Day on which an Annualised Advance is effective.
Estimated Annual Consumption	EAC_KR	kWh	For each Settlement Register, an estimate of Consumption over a year.
Estimated Regional Average Demand Per Customer	Y_HQj	kW	An estimate of customer Consumption by profile and GSP Group in respect of each Settlement Period, determined pursuant to paragraph 6.5 of Annex S-2.
Export Consumption Component Class			a Consumption Component Class as shown in Table X-8 as having a measurement quantity ID of Active Export
Fraction Of Yearly Consumption	FYC_KR		The fraction of annual Consumption allocated to a Meter Advance Period pursuant to paragraph 4.3 of Annex S-2.
Grid Supply Point Group Measured Temperature	T_HT	F	A temperature taken at locations and times from time to time agreed by the Panel and provided by the Temperature Provider pursuant to paragraph 5.2.2 of Annex S-2.
Group Average Annual Consumption	GAAC_HQ	MWh	The average annual Consumption for each GSP Group for each profile as supplied by the Profile Administrator pursuant to paragraph 5.1.4 of Annex S-2.
GSP Group Correction Factor	CF_Hj		The factor by which the relevant components of GSP Group Consumption are adjusted and which is determined pursuant to paragraph 9.2 of Annex S-2.
GSP Group Correction Scaling Weight	WT_N	Number	The weighting for each Consumption Component Class used in GSP Group correction and which is supplied pursuant to paragraph 5.1.5 of Annex S-2.
GSP Group Half Hourly Consumption	GC_HNj	MWh	The GSP Group half hourly Consumption by Consumption Component Class determined pursuant to paragraph 9.1 of Annex S-2.
GSP Group Profile Class Average Estimated Annual Consumption	GGPCAEAC_HPC	kWh	The average Estimated Annual Consumption in respect of a GSP Group, Profile Class and Standard Settlement Configuration determined pursuant to paragraph 5.1 of Annex S-2.
GSP Group Profile Class Default Estimated Annual Consumption	GGPCDEAC_HP	kWh	The average Estimated Annual Consumption provided in respect of a GSP Group and Profile Class pursuant to paragraph 5.1.3 of Annex S-2.
GSP Group Take	GSPGT_Hj	MWh	In relation to a GSP Group and a Settlement Period, the number submitted to the SVAA by the CDCA pursuant to Section R5.7.1(b).
Half Hourly Consumption (Losses)	CLOSS_iNj	MWh	The half hourly Consumption for a Consumption Component Class which is defined as line losses, determined pursuant to paragraph 7.2 or 8.1 of Annex S-2.
Half Hourly Consumption (Losses) by Profile Class	CLOSS_iN(c)Pj	MWh	The half hourly consumption for a Profile Class within a non half hourly active import Consumption Component Class which is defined as being for line losses, determined pursuant to paragraph 9A.2 of Annex S-2.
Half Hourly Consumption (Non Losses)	C_iNj	MWh	The half hourly Consumption for a Consumption Component Class which is defined as not being line losses, determined pursuant to paragraph 7.1 or 8.1 of Annex S-2.
Half Hourly Consumption (Non Losses) by Profile Class	C_iN(c)Pj	MWh	The half hourly consumption for a Profile Class within a non half hourly active import Consumption Component Class which is defined as not being for line losses, determined pursuant to paragraph 9A.1 of Annex S-2.
Half Hourly Demand Disconnection Volume	HDD_Kj	kWh	S-2 3.7.2, derived from SMMC
Half Hourly Disconnection (Losses)	DLOSS_iNj	MWh	The half hourly Demand Disconnection volume for a Consumption Component Class which is defined as line losses, determined pursuant to paragraph 7.2 or 8.2 of Annex S-2.
Half Hourly Disconnection (Non Losses)	D_iNj	MWh	The half hourly Demand Disconnection volume for a Consumption Component Class which is defined as not being line losses, determined pursuant to paragraph 7.1 or 8.2 of Annex S-2.
Half Hourly Storage Consumption (Losses)	SCLOSS_iNj	MWh	In respect of an SVA Storage Facility, the half hourly Consumption for a Consumption Component Class which is defined as line losses, determined pursuant to paragraph 13.5.2 of Annex S-2.
Half Hourly Storage Consumption (Non Losses)	SC_iNj	MWh	In respect of an SVA Storage Facility, the half hourly Consumption for a Consumption Component Class which is defined as not being line losses, determined pursuant to paragraph 13.5.1 of Annex S-2.
Historical Daily Profile Coefficient	DPC_HPRT	Number	A particular Daily Profile Coefficient in respect of a Settlement Day which Settlement Day occurs prior to the 1998 Operational Date and which is determined employing a method authorised by the Executive Committee.
Import Consumption Component Class			A Consumption Component Class as shown in Table X-8 as having a measurement quantity ID of Active Import
Initial Total Annualised Advance	ITAA_HZLPR	KWh	The total of all the Annualised Advances for a Supplier in kWh and in respect of a Profile Class, Line Loss Factor Class, Time Pattern Regime and GSP Group, determined pursuant to paragraph 4.4 of Annex S-2.
Initial Total Annualised Advance (Disconnected)	ITAAD_HZLPR	kWh	The total of all the Annualised Advances for a Supplier in kWh subject to Demand Disconnection and in respect of a Profile Class, Line Loss Factor Class, Time Pattern Regime and GSP Group, determined pursuant to paragraph 4.5 of Annex S-2.
Line Loss Factor	LLF_Lj		A multiplier which, when applied to the value of a SVA Metering System’s Consumption, converts such value into its estimated value at the Grid Supply Point, that is including distribution losses.
Line Loss Factor Class			A set of SVA Metering Systems defined by a Distribution System Operator and relating to any one or more of its Distribution System(s) and that are assigned the same Line Loss Factor for the relevant Settlement Period.

Longest Off Period			A period used in determining profile coefficients for Switched Load Metering Systems and determined pursuant to paragraph 6.6 of Annex S-2.
Longest On Period			A period used in determining profile coefficients for Switched Load Metering Systems and determined pursuant to paragraph 6.6 of Annex S-2.
Low Fraction	LOWF_HPC	Number	The deemed annual Consumption associated with the switched load Settlement Registers expressed as a fraction of total annual Consumption for a Switched Load Metering System, determined pursuant to paragraph 6.6 of Annex S-2.
Low Fraction Consumption	H_HPC	Number	The ratio of electricity Consumption deemed as baseload Consumption during the ‘on’ periods of switched load Time Pattern Regimes to that during the ‘off’ periods of switched load Time Pattern Regimes, determined pursuant to paragraph 6.6 of Annex S-2.
Low Register Profile Coefficient	LRPC_HPCj	Number	The deemed fraction of annual Consumption for a Switched Load Metering System in a Settlement Period recorded on those meter registers which are 'on' during times when there is switched load Consumption at such Metering System, determined pursuant to paragraph 6.6 of Annex S-2.
Matrix Of Regression Coefficients	MRC_Q(aa)(nn)j	Various	The matrix of regression coefficients from time to time supplied by the Profile Administrator pursuant to paragraph 5.1.4 of Annex S-2.
Measurement Class			A classification of Metering Systems which indicates how Consumption is measured i.e. Non Half Hourly Metering Equipment (equivalent to Measurement Class “A”) Non Half Hourly Unmetered Supplies (equivalent to Measurement Class “B”) Half Hourly Metering Equipment at above 100kW Premises (equivalent to Measurement Class “C”) Half Hourly Unmetered Supplies (equivalent to Measurement Class “D”) Half Hourly Metering Equipment at below 100kW Premises with current transformer (equivalent to Measurement Class “E”) Half Hourly Metering Equipment at below 100kW Premises with current transformer or whole current, and at Domestic Premises (equivalent to Measurement Class “F”) Half Hourly Metering Equipment at below 100kW Premises with whole current and not at Domestic Premises (equivalent to Measurement Class “G”).
Measurement Quantity			An indicator to show whether Metered Data in respect of a Metering System is export or import active energy.
Meter Advance	MADV_KR	kWh	The difference recorded for a Settlement Register between one reading, or as the case may be, deemed reading of this register and the next reading or, as the case may be, deemed reading of this register (that is over the Meter Advance Period) used in the determination of Annualised Advance pursuant to paragraph 4.3 of Annex S-2. In the case where such next reading is deemed, the Meter Advance may also be known more particularly as a Deemed Meter Advance in which case it shall have an associated Deemed Meter Advance Period.
Meter Advance Period	MAP		The period of complete Settlement Days between successive meter readings for a Settlement Register, which shall be the period from and including the Settlement Day on which a meter reading is taken up to and including the Settlement Day prior to the Settlement Day on which the next meter reading is taken.
Metered Data			Data concerning the quantities of Active Energy exported or imported measured, collected, recorded and otherwise determined pursuant to the Code.
Metering System Delivered Volumes	QVMD_Kj	MWh	The quantity determined in accordance with paragraph 3.10.2 of Annex S-2.
Metering System Metered Consumption	VMMC_HZaNKji	MWh	The quantity determined in accordance with paragraph 7.1.1B of Annex S-2.
Metering System Period Disconnection Duration	M_Kj	Hours	The duration in hours in a given Settlement Period for which a given Metering System was subject to Demand Disconnection.
Modified Switched Load State Indicator	SQNEW_Cj	Indicator (1 or 0)	A Switched Load State Indicator modified pursuant to paragraph 6.6 of Annex S-2.
Mon_T, Wed_T, Thu_T and Fri_T		Indicators (1 or 0)	A set of indicators whose values are determined pursuant to paragraph 6.5 of Annex S-2.
MSID ABSVD (Non Losses)	MSABSVD_NKji	MWh	The amount determined in accordance with Annex S-2 paragraph 7.1.6
MSID ABSVD (Losses)	MSABSVDL_NKji		The data determined by the SVAA in accordance with Annex S-2 paragraph 7.2.6.
MSID Pair Delivered Volume	MPDV_j	MWh	MSID Pair Delivered Volume is such volumes of Active Energy notified to the SVAA by the NETSO for the purposes of calculating Non BM Unit ABSVD (SNBABSVD_ij); or by the Virtual Lead Party for the purposes of aggregating Secondary BM Unit Supplier Delivered Volume (VBMUSDV_iZj)
MSID Standing Data			The data procured by the SVAA where it has confirmed the allocation of an MSID Pair to a Secondary BM Unit and shall include those data items described in Section S11.2.3.
Net Differencing Volume	VNDK_j	MWh	has the meaning given to it in Section S-2 7.1.1C
Non Half Hourly Supplier Deemed Take	NHHSDT_HZj	MWh	That part of the corrected Supplier Deemed Take associated with those Consumption Component Classes for which the data aggregation type is ‘N’, determined pursuant to paragraph 9.5 of Annex S-2.
Non-BM STOR Instruction Volume	NBSVD_ZaKj	MWh	The estimated volume of demand side Non-BM STOR delivered as determined and notified by the NETSO pursuant to Section S9.2.1.
Noon Effective Temperature	NET_H	F	A temperature determined pursuant to paragraph 6.5 of Annex S-2.
Normal Fraction	NF_HPC	Number	The deemed annual Consumption associated with the non-switched load Settlement Registers expressed as a fraction of total annual Consumption for a Switched Load Metering System determined pursuant to paragraph 6.6 of Annex S-2.
Normal Register Profile Coefficient	NRPC_HPCj	Number	The deemed fraction of annual Consumption for a Switched Load Metering System in a Settlement Period recorded on those meter registers which are 'on' during times when there is no switched load Consumption at such Metering System, determined pursuant to paragraph 6.6 of Annex S-2.
Number of Metering Systems Contributing to the Standard Settlement Configuration Estimated Daily Consumption	NMSSCEDC_HPCT	Number	The number of non half hourly metering systems for which SPM data was used in determining the Standard Settlement Configuration Estimated Daily Consumption pursuant to paragraph 5.1 of Annex S-2.
Number Of Non Half Hourly Metered Metering Systems Requiring A Default Estimated Annual Consumption	NMMDE_HZLPR	Number	The number of non half hourly Settlement Registers within metered SVA Metering Systems without either an Annualised Advance or an Estimated Annual Consumption and which therefore require a Default Estimated Annual Consumption to be determined, the value of which is maintained pursuant to Annex S-2.
Number Of Non Half Hourly Metered Metering Systems Requiring A Default Estimated Annual Consumption (Disconnected)	NMMDED_HZLPR	Number	The number of non half hourly Settlement Registers within metered SVA Metering Systems without either an Annualised Advance or an Estimated Annual Consumption and which therefore require a Default Estimated Annual Consumption to be determined which were subject to Demand Disconnection, the value of which is maintained pursuant to Annex S-2.
Number Of Non Half Hourly Metering Systems Contributing To The Total Annualised Advance	NMA_HZLPR	Number	The number of non half hourly Settlement Registers within SVA Metering Systems contributing to the calculation of Total Annualised Advance, the value of which is maintained pursuant to paragraph 4.4 of Annex S-2.
Number Of Non Half Hourly Metering Systems Contributing To The Total Estimated Annual Consumption	NMME_HZLPR	Number	The number of non half hourly Settlement Registers within metered SVA Metering Systems contributing to the calculation of Total Estimated Annual Consumption, the value of which is maintained pursuant to paragraph 4.4 of Annex S-2.
Number Of Non Half Hourly Metering Systems Contributing To The Total Annualised Advance (Disconnected)	NMAD_HZLPR	Number	The number of non half hourly Settlement Registers within SVA Metering Systems contributing to the calculation of Total Annualised Advance which were subject to Demand Disconnection, the value of which is maintained pursuant to paragraph 4.5 of Annex S-2.
Number Of Non Half Hourly Metering Systems Contributing To The Total Estimated Annual Consumption (Disconnected)	NMMED_HZLPR	Number	The number of non half hourly Settlement Registers within metered SVA Metering Systems contributing to the calculation of Total Estimated Annual Consumption which were subject to Demand Disconnection, the value of which is maintained pursuant to paragraph 4.5 of Annex S-2.
Number Of Non Half Hourly Unmetered Metering Systems Contributing To The Total Estimated Annual Consumption	NMUE_HZLPR	Number	The number of non half hourly Settlement Registers within Unmetered Supplies contributing to Total Estimated Annual Consumption, the value of which is maintained pursuant to paragraph 4.4 of Annex S-2.
Number Of Non Half Hourly Unmetered Metering Systems Contributing To The Total Estimated Annual Consumption (Disconnected)	NMUED_HZLPR	Number	The number of non half hourly Settlement Registers within Unmetered Supplies contributing to Total Estimated Annual Consumption which were subject to Demand Disconnection, the value of which is maintained pursuant to paragraph 4.5 of Annex S-2.
Number Of Non Half Hourly Unmetered Metering Systems Requiring A Default Estimated Annual Consumption	NMUDE_HZLPR	Number	The number of non half hourly Settlement Registers within Unmetered Metering System without an Estimated Annual Consumption and which therefore require a Default Estimated Annual Consumption to be determined, the value of which is maintained pursuant to paragraph 4.4 of Annex S-2.
Number Of Non Half Hourly Unmetered Metering Systems Requiring A Default Estimated Annual Consumption (Disconnected)	NMUDED_HZLPR	Number	The number of non half hourly Settlement Registers within Unmetered Metering System without an Estimated Annual Consumption and which therefore require a Default Estimated Annual Consumption to be determined which were subject to Demand Disconnection, the value of which is maintained pursuant to paragraph 4.5 of Annex S-2.
Period BM Unit Gross Storage Demand			The quantity established in accordance with paragraph 13.5.4 of Annex S-2.
Period Profile Class Coefficient	PPCC_HPRj	Number	The profile coefficient for a Time Pattern Regime associated with a valid combination of Profile Class and Standard Settlement Configuration determined pursuant to paragraph 6.7 of Annex S-2.
Period Time Pattern State Indicator	Q_Rj	Indicator (1 or 0)	An indicator showing for a particular combination of Time Pattern Regime and Standard Settlement Configuration whether the associated Settlement Registers are recording Metered Data, determined pursuant to paragraph 6.4 of Annex S-2.
Previous Estimated Annual Consumption	PEAC_KR	kWh	The value of Estimated Annual Consumption determined pursuant to paragraph 4.3 of Annex S-2.
Primary Supplier's Metering System Metered Consumption	PSMMC_Z1a1K1j or (where applicable) PSMMC_Z1a1.1K1.1j	kWh	The half hourly metered Consumption for a Primary SVA Metering System Number determined pursuant to paragraph 3.5 of Annex S-2.
Profile			A pattern of Consumption specified over a Settlement Day, or part thereof, on a Settlement Period basis.
Profile Class			A classification of profiles which represents an exclusive category of customers whose Consumption can be reasonably approximated to a common profile for Settlement purposes.
Profile Class Estimated Daily Consumption	PCEDC_HPT	kWh	The average Estimated Daily Consumption in respect of a GSP Group, Profile Class, Standard Settlement Configuration and Settlement Day determined pursuant to paragraph 5.1 of Annex S-2.
Quarterly Metering Systems by Supplier	NM_ZqG	Number	The total number of Metering Systems attributed to a Supplier, averaged over a calendar quarter by Supplier Volume Reporting Group, determined pursuant to paragraph 9A.5 of Annex S-2.
Quarterly Supplier Energy Volume	CORC_ZqG	MWh	The total energy volume attributed to a Supplier, summed over a calendar quarter by Supplier Volume Reporting Group, determined pursuant to paragraph 9A.4 of Annex S-2.
Regression Coefficients	RC_HQ(nn)j	Various	A set of regression coefficients determined pursuant to paragraph 6.5 of Annex S-2.
Replica Settlement Day			In relation to a Settlement Day, a Settlement Day having the same attributes as that Settlement Day including any Clock Change.
Rounded-Down Duration	RDD_R(ai)	minutes	The duration of a period employed in the rounding of Time Pattern Regime data and determined pursuant to paragraph 6.4 of Annex S-2.
Rounded-Down Spot Time			A spot time associated with a combination of Time Pattern Regimes and Standard Settlement Configuration employed in the rounding of Time Pattern Regime data and determined pursuant to paragraph 6.4 of Annex S-2.
Rounded-Up Duration	RUD_R(ai)	minutes	The duration of a period employed in the rounding of Time Pattern Regime data and determined pursuant to paragraph 6.4 of Annex S-2.
Rounded-Up Spot Time			A spot time associated with a combination of Time Pattern Regimes and Standard Settlement Configuration employed in the rounding of Time Pattern Regime data and determined pursuant to paragraph 6.4 of Annex S-2.
Secondary BM Unit Delivered Volume	QVBMD_i2NLKji	MWh	The quantity determined in accordance with 7.1.1D Annex S-2.
Secondary BM Unit Demand Volume	VBMUDV_i2j	MWh	The quantity is determined in accordance with 9.6.1B Annex S-2. The energy volume per Settlement Period for a Secondary BM Unit.
Secondary BM Unit Metered Consumption	VBMMC_i2aNLKji	MWh	The Secondary BM Unit half hourly metered Consumption, determined by the SVAA pursuant to paragraph 7.1.1C of Annex S-2.
Secondary BM Unit Supplier Delivered Volume	VBMUSDV_i2ji	MWh	The Secondary BM Unit half hourly Supplier Delivered Volumes determined by the SVAA pursuant to paragraph 9.6.1C of Annex S-2.
Secondary Corrected Component	VCORC_i2Nj	MWh	The quantity determined in accordance with paragraph 9.3.3 of Annex S-2. The Consumption for a SVA Metering System allocated to a Secondary BM Unit after the application of the GSP Group Correction.
Secondary Corrected Delivered Component	VCORDC_i2NKji	MWh	The quantity determined in accordance with paragraph 9.3.4 of Annex S-2 The Delivered Volumes for a SVA Metering System allocated to a Secondary BM Unit after the application of the GSP Group Correction.
Secondary Half Hourly Consumption (Losses)	VLOSS_i2Nj	MWh	The quantity determined in accordance with paragraph 7.2.4 of Annex S-2. The half hourly Consumption for a SVA Metering System allocated to a Secondary BM Unit which is defined as line losses.
Secondary Half Hourly Consumption (Non Losses)	V_i2Nj	MWh	The quantity determined in accordance with paragraph 7.1.4 of Annex S-2. The half hourly Consumption for a SVA Metering System allocated to a Secondary BM Unit which is defined as not being line losses.
Secondary Half Hourly Delivered (Losses)	VDLOSS_i2NKji	MWh	The quantity determined in accordance with paragraph 7.2.5 of Annex S-2. The half hourly Delivered Volumes for a SVA Metering System allocated to a Secondary BM Unit which is defined as not being line losses.
Secondary Half Hourly Delivered (Non Losses)	VD_i2NKji	MWh	The quantity determined in accordance with paragraph 7.1.5 of Annex S-2. The half hourly Delivered Volumes for a SVA Metering System allocated to a Secondary BM Unit which is defined as line losses.
Secondary Supplier's Metering System Metered Consumption	SSMMC_ZnanKnj or (where applicable) SSMMC_Znan.1Kn.1j	kWh	The half hourly metered Consumption for a Secondary SVA Metering System Number determined pursuant to paragraph 3.5 of Annex S-2.
Settlement Class			For a Supplier a unique combination of Profile Class, Line Loss Factor Class, Time Pattern Regime and Standard Settlement Configuration within a GSP Group provided pursuant to paragraph 5.1.6 of Annex S-2.
Settlement Period	j		A period of 30 minutes beginning on the hour or the half hour and in accordance with paragraph 4.3.
Settlement Period Duration	SPD	Hours	0.5 hours.
Settlement Register			A logical register of a Metering System corresponding to one or more physical active import or active export registers (e.g. totalising meters) and, in the case of SVA Metering Systems not subject to half hourly metering, relating to a single valid combination of Time Pattern Regime and Standard Settlement Configuration.
Shared Suppliers' Metering System Metered Consumption	SHMMC_ZaKj	kWh	The half hourly metered Consumption for a SVA Metering System which measures Active Energy that is allocated between a Primary Supplier and the associated Secondary Supplier(s) and which half hourly consumption is determined pursuant to paragraph 3.5 of Annex S-2.
Smoothing Parameter	SPAR	Number	A parameter set by the Panel from time to time is used in the determination of the Annualised Advance Adjustment Factor pursuant to paragraph 4.3 of Annex S-2.
Specimen Settlement Day			In relation to any Settlement Day, a Settlement Day having the same attributes as that Settlement Day other than a Clock Change.
Standard Settlement Configuration			A standard Metering System configuration recognised by the Supplier Volume Allocation Agent System.
Standard Settlement Configuration Estimated Daily Consumption	SSCED_HPCT`	kWh	The average Estimated Daily Consumption in respect of a GSP Group, Profile Class, Standard Settlement Configuration and Settlement Day determined pursuant to paragraph 5.1 of Annex S-2.
Storage Metering System Metered Consumption	SVMMC_HZaNLKji	MWh	The quantity determined in accordance with paragraph 7.1.1D of Annex S-2.
Storage Corrected Component	SCORC_iNj	MWh	The quantity submitted in accordance with paragraph 13.5.3 of Annex S-2.
Sunset Time	SUNT	Minutes	The time duration from the start of the Settlement Day to the time of sunset determined pursuant to paragraph 6.5 of Annex S-2 with reference to the Time of Sunset Data.
Sunset Variable	S	Minutes	The number of minutes after 1800 hours GMT that the sun is deemed to set, determined pursuant to paragraph 6.5 of Annex S-2.
Supplier BM Unit Non BM ABSVD	SNBABSVD_ij	MWh	The amount determined in accordance with Annex S-2 paragraph 9.6.1D.
Supplier Cap Take	SCT_HZj	MWh	The deemed take (active import) at GSP Group level for a SVA Supplier during a Settlement Period pursuant to paragraph 9.7 of Annex S-2.
Supplier Deemed Take	SDT_HZj	MWh	The deemed take at GSP Group level for a SVA Supplier during a Settlement Period determine pursuant to paragraph 9.4 of Annex S-2.
Supplier Disconnection Matrix	SDM_HZaLPR		A matrix of data as determined pursuant to paragraph 4.5 of Annex S-2.
Supplier Purchase Matrix	SPM_HZaLPR		A matrix of data as determined pursuant to paragraph 4.4 of Annex S-2.
Supplier’s Demand Disconnection Volume	SDD_HZaNj	MWh	The half hourly Demand Disconnection volume, determined by a Half Hourly Data Aggregator pursuant to paragraph 3.7 of Annex S-2.
Supplier’s Demand Disconnection Volume (Losses)	SDDL_HZaNj	MWh	The line losses determined by a Half Hourly Data Aggregator as resulting from the Supplier’s Demand Disconnection Volume pursuant to paragraph 3.7 of Annex S-2.
Supplier’s Meter Register Consumption	SMRC__aKJj	kWh	The half hourly metered Consumption for a Settlement Register within a SVA Metering System.
Supplier’s Metered Consumption	SMC_HZaNLj	MWh	The half hourly metered Consumption, determined by a Half Hourly Data Aggregator pursuant to paragraph 3.5 of Annex S-2.
Supplier’s Metered Consumption (Losses)	SMCL_HZaNLj	MWh	The line losses determined by a Half Hourly Data Aggregator as resulting from the Supplier’s Metered Consumption pursuant to paragraph 3.5 of Annex S-2.
Supplier’s Metering System Metered Consumption	SMMC_ZaKj	kWh	The half hourly metered Consumption for a SVA Metering System, determined pursuant to paragraph 3.5 of Annex S-2.
Switched Fraction	SWF_HPC	Number	The deemed proportion of Consumption for a Switched Load Metering System which is switched load determined pursuant to paragraph 6.6 of Annex S-2.
Switched Load Metering System			A Metering System which has a Profile Class classified as Economy 7 and/or such other classification as may be agreed from time to time by the Panel.
Switched Load Profile Coefficient	SLP_HPCj	Number	A number determined pursuant to paragraph 6.6 of Annex S-2 and representing the fraction of annual Consumption in a given Settlement Period for a particular switched load profile.
Switched Load State Indicator	SQ_Cj	Indicator (1 or 0)	An indicator showing if any Time Pattern Regime associated with a switched load within a Standard Settlement Configuration is recording Metered Data in a given Settlement Period, determined pursuant to paragraph 6.6 of Annex S-2.
Teleswitch Contact			One of the logical contacts within each teleswitched meter.
Teleswitch Contact Interval Data			In respect of a Teleswitch Group, the state of a particular Teleswitch Contact within all Metering Systems within such Teleswitch Group at the start of a UTC Day and, for each following change of state of such contact, the new state of such contact and the time in Co-ordinated Universal Time of such change of state.
Teleswitch Contact Rule			The relationship between a Teleswitch Contact and a Teleswitch Register Rule which is notified by a Supplier pursuant to paragraph 5.1.1 of Annex S-2.
Teleswitch Group			A group of Metering Systems which are controlled by the same teleswitch messages which messages are under the control of a particular person.
Teleswitch Interval			A period during which the Settlement Registers associated with a Teleswitch Time Pattern Regime are recording metered consumption and which is determined pursuant to paragraph 6.2 of Annex S-2.
Teleswitch Regime Indicator		Indicator	An indicator indicating whether a Settlement Register is associated with a Time Pattern Regime provided pursuant to paragraph 5.1.5 of Annex S-2.
Teleswitch Register Rule			A rule defining when the Settlement Registers associated with a Teleswitch Time Pattern Regime are recording metered consumption which is notified by a Supplier pursuant to paragraph 5.1.1 of Annex S-2.
Teleswitch Time Pattern Regime			A Time Pattern Regime associated with a teleswitched Standard Settlement Configuration in a particular Teleswitch Group.
Threshold Parameter	TP	Number	A parameter set by the Panel from time to time and used in the determination of the Default Estimated Annual Consumption pursuant to paragraph 4.4 of Annex S-2.
Time of Sunset		Time	A set of data supplied to the Supplier Volume Allocation Agent pursuant to paragraph 5.1.6 of Annex S-2.
Time Pattern Regime			A pattern of switching behaviour through time that determines when a Settlement Register is or is not recording Metered Data provided pursuant to paragraph 5.1.5 of Annex S-2.
Time Pattern Regime Estimated Annual Consumption	TPREAC_HPR	kWh	The average Estimated Annual Consumption in respect of a GSP Group, Profile Class, Standard Settlement Configuration and Time Pattern Regime determined pursuant to paragraph 5.1 of Annex S-2.
Time Pattern Regime Estimated Daily Consumption	TPREDC_HPRT	kWh	The average Estimated Daily Consumption in respect of a GSP Group, Profile Class, Standard Settlement Configuration, Time Pattern Regime and Settlement Day determined pursuant to paragraph 5.1 of Annex S-2.
Timeswitch Regime Indicator		Indicator	An indicator indicating whether a Settlement Register is associated with a Time Pattern Regime provided pursuant to paragraph 5.1.5 of Annex S-2.
Total Annualised Advance	TAA_HZLPR	MWh	The total of all the Annualised Advances for a Supplier in MWh and in respect of a Profile Class, Line Loss Factor Class, Time Pattern Regime and GSP Group determined pursuant to paragraph 4.4 of Annex S-2.
Total Annualised Advance (Disconnected)	TAAD_HZLPR	MWh	The total of all the Annualised Advances for a Supplier in MWh and in respect of a Profile Class, Line Loss Factor Class, Time Pattern Regime and GSP Group which were subject to Demand Disconnection, determined pursuant to paragraph 4.5 of Annex S-2.
Total Estimated Annual Consumption For Non Half Hourly Metered Metering Systems	ME_HZLPR	KWh	The sum of Estimated Annual Consumption for non half hourly metered SVA Metering Systems calculated pursuant to paragraph 4.4 of Annex S-2.
Total Estimated Annual Consumption For Non Half Hourly Metered Metering Systems (Disconnected)	MED_HZLPR	kWh	The sum of Estimated Annual Consumption for non half hourly metered SVA Metering Systems which were subject to Demand Disconnection, determined pursuant to paragraph 4.5 of Annex S-2.
Total Metered Estimated Annual Consumption	TMEAC_HZLPR	MWh	The total metered annual Consumption for a SVA Supplier and in respect of a Profile Class, Line Loss Factor Class, Time Pattern Regime and GSP Group, determined pursuant to paragraph 4.4 of Annex S-2.
Total Metered Estimated Annual Consumption (Disconnected)	TMEACD_HZLPR	MWh	The total metered annual Consumption for a SVA Supplier subject to Demand Disconnection and in respect of a Profile Class, Line Loss Factor Class, Time Pattern Regime and GSP Group, determined pursuant to paragraph 4.5 of Annex S-2.
Total Number Of Metered Non Half Hourly Metering Systems Contributing To Total Metered Estimated Annual Consumption	TMEACC_HZLPR	Number	The number of metered non half hourly Settlement Registers within SVA Metering Systems contributing to the calculation of Total Metered Estimated Annual Consumption the value of which is maintained pursuant to paragraph 4.4 of Annex S-2.
Total Number Of Metered Non Half Hourly Metering Systems Contributing To Total Metered Estimated Annual Consumption (Disconnected)	TMEACCD_HZLPR	Number	The number of metered non half hourly Settlement Registers within SVA Metering Systems contributing to the calculation of Total Metered Estimated Annual Consumption which were subject to Demand Disconnection, the value of which is maintained pursuant to paragraph 4.5 of Annex S-2.
Total Number Of Non Half Hourly Unmetered Metering Systems Contributing To Total Unmetered Consumption	TMUEC_HZLPR	Number	The number of non half hourly Settlement Registers within Unmetered Supplies contributing to the calculation of Total Unmetered Consumption the value of which is maintained pursuant to paragraph 4.4 of Annex S-2.
Total Number Of Non Half Hourly Unmetered Metering Systems Contributing To Total Unmetered Consumption (Disconnected)	TMUECD_HZLPR	Number	The number of non half hourly Settlement Registers within Unmetered Supplies contributing to the calculation of Total Unmetered Consumption which were subject to Demand Disconnection, the value of which is maintained pursuant to paragraph 4.5 of Annex S-2.
Total Unmetered Consumption	TUE_HZLPR	MWh	The total unmetered annual Consumption for a SVA Supplier and in respect of a Profile Class, Line Loss Factor Class, Time Pattern Regime and GSP Group, determined pursuant to paragraph 4.4 of Annex S-2.
Total Unmetered Consumption (Disconnected)	TUED_HZLPR	MWh	The total unmetered annual Consumption for a SVA Supplier subject to Demand Disconnection and in respect of a Profile Class, Line Loss Factor Class, Time Pattern Regime and GSP Group, determined pursuant to paragraph 4.5 of Annex S-2.
Unadjusted Annual Fraction of Consumption	UAFYC_HPR		An estimate of the fraction of the total average consumption of a multi-register Standard Settlement Configuration attributable to each Time Pattern Regime of that Standard Settlement Configuration, prior to adjustment for rounding errors, determined pursuant to paragraph 5.1 of Annex S-2.
Unadjusted Interval			A period of time beginning at an Unadjusted Interval Start Time and ending at its associated Unadjusted Interval End Time, determined pursuant to paragraph 6.4 of Annex S-2.
Unadjusted Interval End Time	UIET_X(ai)		A time associated with a particular Time Pattern Regime determined pursuant to paragraph 6.4 of Annex S-2.
Unadjusted Interval Start Time	UIST_X(ai)		A time associated with a particular Time Pattern Regime determined pursuant to paragraph 6.4 of Annex S-2.
Unrounded Duration	UD_X(ai)	Minutes	The time duration of an Unadjusted Interval determined pursuant to paragraph 6.4 of Annex S-2.
Value Of Estimated Annual Consumption For Non Half Hourly Unmetered Metering Systems	UE_HZLPR	KWh	The value of Estimated Annual Consumption for non half hourly Settlement Registers within Unmetered Supplies, the value of which is maintained pursuant to paragraph 4.4 of Annex S-2.
Value Of Estimated Annual Consumption For Non Half Hourly Unmetered Metering Systems (Disconnected)	UED_HZLPR	kWh	The value of Estimated Annual Consumption for non half hourly Settlement Registers within Unmetered Supplies which were subject to Demand Disconnection, the value of which is maintained pursuant to paragraph 4.5 of Annex S-2.

Table X–7 - List of Acronyms Applicable to Section S

This table provides a list of the acronyms defined in Table X-6, presented in alphabetical order of the acronym name.

Acronym	Corresponding Defined Term or Expression
AAAF_KR	Annualised Advance Adjustment Factor
AAFYC_HPC	Alternative Average Fraction of Yearly Consumption
AA_KR	Annualised Advance
ABDD_iaNLKj	Allocated BM Unit’s Demand Disconnection Volume
ABMMMC _iaNLKj	Allocated BM Unit's Metering System Metered Consumption
AFYCA_HPC	Annual Fraction of Yearly Consumption Adjustment
AFYC_HPR	Average Fraction Of Yearly Consumption
AQVMD_NLKji	ABSVD BM Unit Delivered Volume
ASDD_HZaNLKj	Allocated Supplier’s Demand Disconnection Volume
ASMMC_HZaNLKj	Allocated Supplier’s Metering System Metered Consumption
AVMMC_HZaNLKji	Allocated Metering System Metered Consumption
BAP_HQj	Baseload Profile Coefficient
BF_HPC	Base Fraction
BMDD_iaNj	BM Unit’s Demand Disconnection Volume
BMDDL_iaNj	BM Unit’s Demand Disconnection Volume (Losses)
BMDM_iaLPR	BM Unit Disconnection Matrix
BMMC_iaNLj	BM Unit's Metered Consumption
BMMCL_iaNLj	BM Unit's Metered Consumption (Losses)
BMPC_iLPRj	BM Unit's Profiled Consumption
BMPD_iLPRj	BM Unit’s Profiled Disconnection
BMPM_iaLPR	BM Unit Purchase Matrix
BMUADDV_ij	BM Unit Allocated Demand Disconnection Volume
BMUADV_ij	BM Unit Allocated Demand Volume
CF_Hj	GSP Group Correction Factor
C_iN(c)Pj	Half Hourly Consumption (Non Losses) by Profile Class
C_iNj	Half Hourly Consumption (Non Losses)
CLOSS_iN(c)Pj	Half Hourly Consumption (Losses) by Profile Class
CLOSS_iNj	Half Hourly Consumption (Losses)
CORC_iN(c)Pj	Corrected Component by Profile Class
CORC_iNj	Corrected Component
CORC_ZqG	Quarterly Supplier Energy Volume
CORDC_iNj	Corrected Disconnection Component
DDDPC_HPKRT	Demand Disconnection Daily Profile Coefficient
DEM_HZLPR	Default Estimated Annual Consumption For Metered Metering Systems
DEU_HZLPR	Default Estimated Annual Consumption For Unmetered Metering Systems
D_iNj	Half Hourly Disconnection (Non Losses)
DLOSS_iNj	Half Hourly Disconnection (Losses)
DMA_KR	Deemed Meter Advance
DPC_HPRT	Daily Profile Coefficient
DPC_HPRT	Historical Daily Profile Coefficient
EAC_KR	Estimated Annual Consumption
FYC_KR	Fraction Of Yearly Consumption
GAAC_HQ	Group Average Annual Consumption
GC_HNj	GSP Group Half Hourly Consumption
GGPCAEAC_HPC	GSP Group Profile Class Average Estimated Annual Consumption
GGPCDEAC_HP	GSP Group Profile Class Default Estimated Annual Consumption
HDD_Kj	Half Hourly Demand Disconnection Volume
H_HPC	Low Fraction Consumption
ITAAD_HZLPR	Initial Total Annualised Advance (Disconnected)
K1_HPC
K2_HPC
LLF_Lj	Line Loss Factor
LOWF_HPC	Low Fraction
LRPC_HPCj	Low Register Profile Coefficient
MADV_KR	Meter Advance
MAP	Meter Advance Period
MED_HZLPR	Total Estimated Annual Consumption For Non Half Hourly Metered Metering Systems (Disconnected)
M_Kj	Metering System Period Disconnection Duration
MPDV_j	MSID Pair Delivered Volume
MRC_Q(aa)(nn)j	Matrix Of Regression Coefficients
MSABSVDL_HZLKj	MSID ABSVD (Losses)
MSABSVD_NKji	MSID ABSVD (Non Losses)
NBSVD_ZaKj	Non-BM STOR Instruction Volume
NET_H	Noon Effective Temperature
NF_HPC	Normal Fraction
NHHSDT_HZj	Non Half Hourly Supplier Deemed Take
NMAD_HZLPR	Number Of Non Half Hourly Metering Systems Contributing To The Total Annualised Advance (Disconnected)
NMA_HZLPR	Number Of Non Half Hourly Metering Systems Contributing To The Total Annualised Advance
NMMDED_HZLPR	Number Of Non Half Hourly Metered Metering Systems Requiring A Default Estimated Annual Consumption (Disconnected)
NMMDE_HZLPR	Number Of Non Half Hourly Metered Metering Systems Requiring A Default Estimated Annual Consumption
NMMED_HZLPR	Number Of Non Half Hourly Metering Systems Contributing To The Total Estimated Annual Consumption (Disconnected)
NMME_HZLPR	Number Of Non Half Hourly Metering Systems Contributing To The Total Estimated Annual Consumption
NMSSCEDC_HPCT	Number of Metering Systems Contributing to the Standard Settlement Configuration Estimated Daily Consumption
NMUDED_HZLPR	Number Of Non Half Hourly Unmetered Metering Systems Requiring A Default Estimated Annual Consumption (Disconnected)
NMUDE_HZLPR	Number Of Non Half Hourly Unmetered Metering Systems Requiring A Default Estimated Annual Consumption
NMUED_HZLPR	Number Of Non Half Hourly Unmetered Metering Systems Contributing To The Total Estimated Annual Consumption (Disconnected)
NMUE_HZLPR	Number Of Non Half Hourly Unmetered Metering Systems Contributing To The Total Estimated Annual Consumption
NM_ZqG	Quarterly Metering Systems by Supplier
NRPC_HPCj	Normal Register Profile Coefficient
ORABSVDC_i2Nj	Corrected MSID ABSVD Component
PCEDC_HPT	Profile Class Estimated Daily Consumption
PEAC_KR	Previous Estimated Annual Consumption
P_HQj	Basic Period Profile Coefficient
PPCC_HPRj	Period Profile Class Coefficient
PSMMC_Z1a1.1K1.1j	Primary Supplier's Metering System Metered Consumption for Secondary SVA Metering System Number K1.1
PSMMC_Z1a1K1j	Primary Supplier's Metering System Metered Consumption for Secondary SVA Metering System Number K1
Q_Rj	Period Time Pattern State Indicator
QVBMD_i2NLKji	Secondary BM Unit Delivered Volume
QVMD_Kj	Metering System Delivered Volume
RC_HQ(nn)j	Regression Coefficients
RDD_R(ai)	Rounded-Down Duration
RUD_R(ai)	Rounded-Up Duration
S	Sunset Variable
SC_iNj	Half Hourly Storage Consumption (Non Losses)
SCLOSS_iNj	Half Hourly Storage Consumption (Losses)
SCORC_iNj	Storage Corrected Component
SDD_HZaNj	Supplier’s Demand Disconnection Volume
SDDL_HZaNj	Supplier’s Demand Disconnection Volume (Losses)
SDM_HZaLPR	Supplier Disconnection Matrix
SDT_HZj	Supplier Deemed Take
SHSMMC_ZaKj	Shared Suppliers' Metering System Metered Consumption
SIX_PM
SLP_HPCj	Switched Load Profile Coefficient
SMC_HZaNLj	Supplier's Metered Consumption
SMCL_HZaNLj	Supplier’s Metered Consumption (Losses)
SMMC_ZaKj	Supplier’s Metering System Metered Consumption
SMRC__aKJj	Supplier’s Meter Register Consumption
SNBABSVD_ij	Supplier BM Unit Non BM ABSVD
SPAR	Smoothing Parameter
SPD	Settlement Period Duration
SPM_HZaLPR	Supplier Purchase Matrix
SQ_Cj	Switched Load State Indicator
SSCED_HPCT	Standard Settlement Configuration Estimated Daily Consumption
SSMMC_Znan.1Kn.1j	Secondary Supplier's Metering System Metered Consumption for Secondary SVA Metering System Number Kn.1
SSMMC_ZnanKnj	Secondary Supplier's Metering System Metered Consumption for Secondary SVA Metering System Number Kn
SUNT	Sunset Time
SVMMC_HZaNLKji	Storage Metering System Metered Consumption
SWF_HPC	Switched Fraction
TAAD_HZLPR	Total Annualised Advance (Disconnected)
T_HT	Grid Supply Point Group Measured Temperature
TMEACCD_HZLPR	Total Number Of Metered Non Half Hourly Metering Systems Contributing To Total Metered Estimated Annual Consumption (Disconnected)
TMEACD_HZLPR	Total Metered Estimated Annual Consumption (Disconnected)
TMUECD_HZLPR	Total Number Of Non Half Hourly Unmetered Metering Systems Contributing To Total Unmetered Consumption (Disconnected)
TPREAC_HPR	Time Pattern Regime Estimated Annual Consumption
TPREDC_HPRT	Time Pattern Regime Estimated Daily Consumption
TUED_HZLPR	Total Unmetered Consumption (Disconnected)
UAFYC_HPR	Unadjusted Annual Fraction of Consumption
UED_HZLPR	Value Of Estimated Annual Consumption For Non Half Hourly Unmetered Metering Systems (Disconnected)
VBMMC_i2aNLKji	Secondary BM Unit Metered Consumption
VBMUDV_i2j	Secondary BM Unit Demand Volume
VBMUSDV_i2ji	Secondary BM Unit Supplier Delivered Volume
VCORC_i2Nj	Secondary Corrected Component
VCORDC_i2NKji	Secondary Corrected Delivered Component
VD_i2NKji	Secondary Half Hourly Delivered (Non Losses)
VDLOSS_i2NKji	Secondary Half Hourly Delivered (Non Losses)
V_i2Nj	Secondary Half Hourly Consumption (Non Losses)
VLOSS_i2Nj	Secondary Half Hourly Delivered (Losses)
VMMC_HZaNLKji	Metering System Metered Consumption
WT_N	GSP Group Correction Scaling Weight
y_HQj	Estimated Regional Average Demand Per Customer

Table X-8

List of Valid Consumption Component Classes

The following table shows a list of valid Consumption Component Classes. The Panel may amend such list of valid Consumption Component Classes from time to time.

Consumption Component Class Id	Measurement Quantity ID	Data Aggregation Type	Metered / Unmetered Indicator	Consumption Component Indicator	Actual / Estimated Indicator	AA / EAC Indicator	Consumption Level Indicator	Measurement Class
1	AI	H	M	C	A		B	C
2	AI	H	U	C	A		-	D
3	AI	H	M	M	A		B	C
4	AI	H	M	L	A		B	C
5	AI	H	U	L	A		-	D
6	AE	H	M	C	A		-	C
7	AE	H	M	M	A		-	C
8	AE	H	M	L	A		-	C
9	AI	H	M	C	E		B	C
10	AI	H	U	C	E		-	D
11	AI	H	M	M	E		B	C
12	AI	H	M	L	E		B	C
13	AI	H	U	L	E		-	D
14	AE	H	M	C	E		-	C
15	AE	H	M	M	E		-	C
16	AE	H	M	L	E		-	C
17	AI	N	M	C		E	-	A
18	AI	N	M	C		A	-	A
19	AI	N	U	C		E	-	B
20	AI	N	M	L		E	-	A
21	AI	N	M	L		A	-	A
22	AI	N	U	L		E	-	B
23	AI	H	M	C	A		A	E
25	AI	H	M	M	A		A	E
26	AI	H	M	L	A		A	E
28	AI	H	M	C	E		A	E
30	AI	H	M	M	E		A	E
31	AI	H	M	L	E		A	E
32	AE	N	M	C		E	-	A
33	AE	N	M	C		A	-	A
34	AE	N	M	L		E	-	A
35	AE	N	M	L		A	-	A
36	AE	H	M	C	A		-	E
37	AE	H	M	M	A		-	E
38	AE	H	M	L	A		-	E
39	AE	H	M	C	E		-	E
40	AE	H	M	M	E		-	E
41	AE	H	M	L	E		-	E
42	AI	H	M	C	A		A	F
43	AI	H	M	M	A		A	F
44	AI	H	M	L	A		A	F
45	AI	H	M	C	E		A	F
46	AI	H	M	M	E		A	F
47	AI	H	M	L	E		A	F
48	AE	H	M	C	A		-	F
49	AE	H	M	M	A		-	F
50	AE	H	M	L	A		-	F
51	AE	H	M	C	E		-	F
52	AE	H	M	M	E		-	F
53	AE	H	M	L	E		-	F
54	AI	H	M	C	A		A	G
55	AI	H	M	M	A		A	G
56	AI	H	M	L	A		A	G
57	AI	H	M	C	E		A	G
58	AI	H	M	M	E		A	G
59	AI	H	M	L	E		A	G
60	AE	H	M	C	A		-	G
61	AE	H	M	M	A		-	G
62	AE	H	M	L	A		-	G
63	AE	H	M	C	E		-	G
64	AE	H	M	M	E		-	G
65	AE	H	M	L	E		-	G

The attributes of such Consumption Component Classes are for the time being and from time to time valid:

(i) measurement quantity ID, which shall have values:

AI active import (consumption); or

AE active export (generation);

(ii) data aggregation type, which shall have values:

H half hourly; or

N non-half hourly;

(iii) metered/ unmetered indicator shall have values:

M metered; or

U unmetered;

(iv) consumption component indicator shall have values:

C basic consumption (or generation);

M metering system specific line losses; or

L metering system non-specific line losses;

(v) actual/ estimated indicator shall have values:

A actual;

E estimated; or

Null;

(vi) AA/EAC indicator shall have values:

A Annualised Advance;

E Estimated Annual Consumption; or

Null; and

(vii) Consumption Level Indicators shall have the following values:

A Metering Systems which are not 100kW Metering Systems (equivalent to Measurement Class "E", "F" and "G");

B Metering Systems which are 100kW Metering Systems (equivalent to Measurement Class "C"); or

Null Not applicable, shown as a hyphen (-), including export, NHH and unmetered MSIDs.

viii) Measurement Class as defined in Table X-6.

Table X–9

List of Supplier Volume Reporting Groups and associated relationships used for the purposes of the Supplier Quarterly Volume Report determined according to paragraph 9A of Annex S-2:

Supplier Volume Reporting Group	Consumption Component Classes	Profile Classes (where used and/or applicable)
1	17, 18, 20, 21	1, 2
2	17, 18, 20, 21	3, 4
3	17, 18, 20, 21	5, 6, 7, 8
4	19, 22	Not used
5	32, 33, 34, 35	Not used
6	1, 3, 4, 9, 11, 12, 23, 25, 26, 28, 30, 31, 42, 43, 44, 45, 46, 47, 54, 55, 56, 57, 58, 59	Not applicable
7	2, 5, 10, 13	Not applicable
8	6, 7, 8, 14, 15, 16, 36, 37, 38, 39, 40, 41, 48, 49, 50, 51, 52, 53, 60, 61, 62, 63, 64, 65	Not applicable

For the Supplier Quarterly Volume Report as set out in paragraph 4.2.10 of Section V, the Supplier Volume Reporting Groups with the numbers in the far left column of the table above shall be given the following descriptive labels in the actual report:

1. "Non half hourly metered import, Profile Classes 1 and 2";

2. "Non half hourly metered import, Profile Classes 3 and 4";

3. "Non half hourly metered import, Profile Classes 5, 6, 7 and 8";

4. "Non half hourly unmetered import";

5. "Non half hourly metered export";

6. "Half hourly metered import";

7. "Half hourly unmetered import"; and

8. "Half hourly metered export".

CONTENTS

BSC Section X-2: Technical Glossary V51.0

ANNEX X-2: TECHNICAL GLOSSARY

1. GENERAL

1.1 Introduction

1.2 Use of Mathematical Operators

2. TECHNICAL TERMS AND INTERPRETATION APPLYING EXCEPT IN RELATION TO SECTION S

2.1 Introduction

2.2 Use of Subscripts and Other Expressions

2.3 Glossary of Terms

2.4 Sign Convention - Active Energy and Active Power

2.5 Sign Convention - Cashflows

2.6 Use of Summations

3. TECHNICAL TERMS AND INTERPRETATION APPLYING IN RELATION TO SECTION S

3.1 Introduction

3.2 Use of Subscripts and Other Expressions

3.3 Use of Summations

3.4 Glossary of Terms

3.5 Consumption Component Classes

3.6 Linear Interpolation of Variables

3.7 Sign Convention

4 TIMING CONVENTIONS

4.1 Introduction

4.2 Spot Time

4.3 Settlement Period Times

4.3A Quarter Hour Times

4.4 Point Variables

4.5 Interpolation of Values of Point Variables Between Spot Times Supplied

4.6 Evaluation of Period Variables from Supplied and Interpolated Spot Variables

Table X–1 -Use of Subscripts and Superscripts Applying Except in Relation to Section S

Table X–2 - Terms and Expressions Applying Except in Relation to Section S

Table X-3 - Glossary of Acronyms Applying Except In Relation To Section S

Table X–4 - Use of Subscripts and Superscripts Applying to Section S

Table X–5 - Use of Summations Applying to Section S

Table X–6 - Definitions Applying To Section S

Table X–7 - List of Acronyms Applicable to Section S

Table X-8

List of Valid Consumption Component Classes

Table X–9