This object stores the near end and far end location of all inter shelf spans that were added to/deleted from the UMC system when umc1TrapShelfSpanTableChange trap was emitted by the agent with umc1ShelfSpanTableChangeHistoryIndex sequence number. The umc1ShelfSpanTableChangeHistoryData contains multiple shelf span entries corresponding to the all inter shelf spans that were added to/deleted from the UMC system. Each entry in the umc1ShelfSpanTableChangeHistoryData consisting of action byte followed by packed shelf span record. For initial implementation the OCTET representation will be as follows: Octet[0] Version number (currently 0x01) The contents of the remaining octets are defined as follows for version 0x01. octet[1] Holds the number of spans in this history record. octets[2] through [12] hold the packed record for the 1st Shelf Span being reported. Octet[2] Length of Record Octet[3] Action object which specifies that the record attached after the action object has been added to/deleted from the umc1ShelfSpanTable. See DbActionType for valid values of this byte. Octet[4] Near End Terminal Id Octet[5] Near End Shelf Id Octet[6] Near End Slot Id Octet[7-8] Near End plug-in type Octet[9] Far End Shelf Id Octet[10] Far End Slot Id Octet[11-12] Far End plug-in type octets[13] through [22] hold the packed record for the next Shelf span and so forth, until up to octet[1] number of spans have been defined.