A number of documentation issues have arisen with the Generation Unit ID data item that requires correction: (Please note that schema 6.1 is correct and does not require change.)
• ‘Generation Unit ID’ is a data item that appears on numerous market messages in the schema in all versions of the market design.
• Under SEM another entity (a wholesale definition) called ‘Generator Unit ID’ is introduced. This is part of the retail market design from version 6.0 onward. However, ‘Generator Unit ID’ has not been added to the schema and should not appear as a field in any market message documentation.
• Under SEM, the message field ‘Generation Unit ID’ is modified to carry one of a range of entities, depending on context. These entities are ‘Generator Unit ID’, ‘Arrangement ID’ or the legacy 3 digit ‘Generation Unit ID’.
• In ARIS v6.0 ‘Generator Unit ID’ was incorrectly used in place of ‘Generation Unit ID’ in some message definitions (341, 594, 597 & 598). Some MCRs incorrectly use this term in text but do not introduce the error into the market design. Generator Unit ID is also referenced in supporting text in a number of places.