LPs frequently come with advertisements for recommended other releases on the same label on the back cover. E.g. here Release “Sing und swing mit Ted” by Ted Herold - Cover art - MusicBrainz.
Is there a way to encode this besides putting it in the annotation? Has there been any discussion about adding this as a release-release relationship?
In the old days this was very common. The LP sleeve/liner might be non-printed, have release notes, have pictures of other albums on that label, just anything. I have a lot of CDs that the booklet has other albums to buy. After Dick Freeland (Rebel Records original owner) moved from Maryland to West Virginia he use to include a sheet of paper with all kinds of things to buy (mostly stickers and patches). I am not sure of a relationship value except where it credits something no one knows about. The artwork is always valuable. In the 60’s the same release of a LP could have differently printed LP liners/sleeves with different advertisements. Just my thoughts.
Value in a concrete case for me was proving that a release is younger than originally thought because it referenced a “later” release. And then I thought more generally, if we have the info, why not encode it?
I have kept that kind of information in the edit notes, annotation, and disambiguation, depending on what it is. I do believe you make a good case for having something that can be referenced. I would like to see more discussion on how to do this and what would be included, it could get subjective.
Agree it makes more sense in the annotation. That way you can add the speculation as to the date. I’ve added notes before along the lines of “must be a post xxxx release due to the advert for their later album”.