Thanks for your help so far! One more question - what to do so that when the issue has only a year and month, it does not display something like - 1990-09-00, only 1990-09. I've had several situations like this. "00" is added unnecessarily when a release has no release day.
Edit: One more thing - using your suggestion for guest appearances, in a situation where there is no guest appearance - nothing is tagged in the artist name tag. This causes a problem in particular when I want to tag a Various Artists release like this: https://www.discogs.com/release/1127053-Various-CMJ-Presents-Certain-Damage-Volume-38
Wouldn't it be better if it tagged the name of the artist and the guest appearance next to it?
The full date is a bit tricky because not all releases have it.
My routine for tagging is first tagging with MusicBrainz that write date and original date. I uncheck write original release date to date and use year instead of full date. That write full date when available in %DATE% and %ORIGINAL RELEASE DATE%.
Second step with discogger. I have disabled %DATE% to not overwrite the previous. I write the tags
DISCOGS_RELEASE_MONTH %RELEASE_MONTH%
DISCOGS_RELEASE_DAY %RELEASE_DAY%
DISCOGS_RELEASE_YEAR %RELEASE_YEAR%
DISCOGS_RELEASED %RELEASE_DATE_RAW%
DISCOGS_MASTER_RELEASE_YEAR %MASTER_RELEASE_YEAR%
Then I fill the %DATE%, %RELEASE DATE% and %ORIGINAL RELEASE DATE% manually with that info. It is not always available, even using the 2 taggers, so I use the https://github.com/Wil-B/Biography to get info from wikipedia, last.fm and allmusic.
As %DATE% is the most normal tag used for others programs I like that it have the original release date but that a personal taste.
A Various Artist release
The code in the Title + Trcak Artist field is
%TITLE%[' ['%SUBTITLE%']'][' ('$meta_sep(REMIXED BY,', ',' & ')' Remix)'][>>' | '$if(%TRACK ARTIST%,$meta_sep(ARTIST,', ',' & ')[' Featuring '$meta_sep(FEATURING,', ',' & ')],)<<]
Note the %TRACK ARTIST% tag. This is a foobar internal mapping. It is present when %ALBUM ARTIST% is present and is different for the %ARTIST% tag. With this the artist is only displayed when is different from the album artist
I like to have the %album artist%, %artist% and %title% write as tis released and in a single value. This is useful with other players (like car player) and for scrobbling to last.fm. Then I used other tags like %artists%, %featuring%, % remixed by%, %producer%, etc as separate multivalues. Mostly to display in facets, make auto-playlists, google searching and uses it in the bio panel.
The decision to add the remixer to tiitle or the featuring to artist is a personal taste, but the way is displayed depend on the component that is used for the playlist. You must search a way to modifies the playlist component you are using to your personal taste.