As I understand it, the normal procedure when adding a release is to create a new release entity for each alternate medium format (e.g. CD, vinyl and digital) using one release group to tie them together. However, some editors will add only one release and attach all related links to it, including adding digital download/streaming links to physical releases. In conjunction with MBS-9499, I propose that https://musicbrainz.org/doc/Style/Relationships/URLs be updated to discourage this practice and remind editors that URLs should match the exact instance of a release. Similarly, there should be a reminder/link in https://musicbrainz.org/doc/Style/Release.

Some sample wording:

URLs should match the exact instance of a release. Links to digital download or streaming sites such as iTunes, Spotify, etc. should be reserved for Digital Media releases.