@IvanDobsky, we’re not talking here about different releases, but about multiple disc IDs attached to a single release:
Freso’s example includes a library URL, which could be useful for verification by another editor who had access to that same library and thus could get the same physical copy.
Another thought: if I have scanned my physical disc and uploaded it to cover art, it could be potentially useful to know that the disc ID came from that same disc.