6.4.2 BlockIDs

All Blocks contain a BlockID Cell. The first Block in the Sales Report Messages shall have a BlockID containing the value 1, the next Block shall  have a BlockID containing the value 2, etc. 

This mechanism allows all Records in a Block to be associated with one another. If, for instance, a Block contains a Head Release, a number or Resources and a few Sub-Releases, the BlockID can be used to link the Sub-Releases to the Head Release. Together with the ReleaseRecordCell, the BlockID also allows to unambiguously link a Sub-Release to its containing Resources.