aggregation over multiple sources (NAS systems)

[simoncn]

There is no formal standard for tag names or tag values (such as genre names). The tagging standards allow you to use any tag names and values, subject to some technical limitations (for example, a tag name in a FLAC file can't contain the '=' character).

MinimServer supports all tag names and values, subject to technical limitations of the various tagging formats. Most tagging programs also do this but some tagging programs are more restrictive. Also, most tagging programs (for example, Mp3tag) have some predefined tag names and also allow the user to add their own custom names.

There are online databases (for example, MusicBrainz) containing tag names and values for a large number of albums and songs. The quality of the data is variable, so you can't assume that everything in the database is correct. If you use a program that takes tag values from these databases and applies them to your files (such as SongKong), your tag names and values will match those used by the program.

If you purchase music downloads, the files will come with a small set of standard tags such as Album, Title, Artist, AlbumArtist, Date, Genre and possibly Composer. Beyond these, my advice is to find a tagging scheme that works for the way you browse your library rather than feeling constrained to conform to some supposed industry standard.