I'm confused, but it's probably because of some 'Lost in Translation'.
I want to define tags in musicbee that only displays in the Vorbis Comment, for sorting?
That sounds like you want to have MusicBee write a tag only to files that use Vorbis Comment (e.g. FLAC and OPUS), but not have it written to mp3, apple formats etc.?
Why? (I don't think it's possible either)
i try to use Custom and Virtual tag but no field "releasetype", what should i do?
I can't make any sense out of that sentence.
Perhaps try again with different wording?
Or maybe somebody else understands what you mean by this.