The Release List section defines the different releases that make up the "product" being delivered. For example, a standard ten-track album will contain one album release and 10 track releases, for a total of 11 Releases.
The album level release is typically represented by the release reference R0 and the track releases by release reference R1, R2, R3, etc. dependent upon their order in the track listing. For each Release, the resources ("tracks") included in the respective release are listed along with their sequence. These resources are referenced back to resources in the Resource List. For example, the Release for Track 1 references the Resource identified by Resource Reference A1, Track 2 by Resource Reference A2, Track 3 by Resource Reference A3, etc.
The metadata defined for each Release includes one or more Release identifiers (ICPN, UPC, EAN, GRid, ISRC), artist, title, label, genre, parental warning and P&C credits. A Release does NOT contain any information regarding the business terms associated with its commercial exploitation and usage.
The exact fields to to be used in a specific business case (e.g. describing a Ringtone release or describing or a Classical Album) is defined in the relevant Release Profile standard. More details on profiling can be found here.