How to handle "extra releases" linked to a specific release?

[yindesu]

@SneakittyCat

If you look into VAGRANCY’s release group, the Animate version has been added to it, with “Snowdrop” listed as a third medium.

I don’t really agree with this way of doing things, because this is not a variation of the VAGRANCY album. You can look it up on Shikata’s official page for the album, but VAGRANCY is a digipak with two tray slots for its two CD’s (AURA-0041 and AURA-0042), and “Snowdrop” is physically separate, with its own jewel case, cover art and booklet (you can see it for example on this auction item). Which, to me, clearly indicates it should be its own release.

If Animate actually sold a set that was packaged together and has its own barcode on the whole set, then it should be its own release. However, the auction shows that the barcode is attached to the retailer bonus jewel case, and doesn’t identify the other release which has a different barcode, and so it’s clearly separate. It’s been previously answered for normal Japanese industry practice that the regular release should be separated from the retailer bonus. e.g. see https://beta.musicbrainz.org/release-group/31b6c6f4-d6c0-4889-ba17-83cd607da976 which has examples of both retailer-exclusive editions and retailer bonuses given alongside a normal release.

Technically the retailer bonuses should be in their own release groups (because they are not versions of the album) and the retailer bonus linked to all applicable releases using Relationship type / Supporting release - MusicBrainz.