For assigning musicbrainz IDs to digital media releases downloaded from online shops, it would be helpful to gather the necessary metadata at a larger scale than just everyone picking the release semi-manually after download.
In many cases, these assignments could be automated by having “purchase for download” external links to the right point in the online shop. Users who download files from their vendors in a structured way (say, wget -m and unzipping in that place) can then utilize that information with minimal scripting effort, provided the vendor has some consistency in their naming (those I’ve used largely do; hyperion is a bit tricky as they have some aliasing). I’d like to use it that way.
In contrast, the relation URL guide says to “[not] try to link widely available releases to every online store” – meaning that I’d need to track that information … somewhere outside MusicBrainz (which I’d really rather not).
So my question is: Does MusicBrainz have concrete guidance (or could the community develop at least rough consensus on) on which stores are OK to include, and where to put that information if it’s not? If such links are useful to a larger number of stores than we want to have shown, would it make sense to have a “is additionally availaboe for purcase for download” at relationship (or flag on the purchase-for-download rel) that would allow having that data in the DB?
(I’m aware there are additional challenges to be tackled to have this use case applicable generally (batch edit when stores change their URI structures, canonicalization) – but getting a feeling of the general acceptance of many of those links would be a good starting point.)