Where can I find some technical info abaout the ID3 TAGS that WMP11 uses on mp3 files?

I�m using Mp3Tag and I need som info on how to add columns to the tags viw of any MP3 file that i add to the list, for example, the programs is telling me that %title% means title of the song and that %artist% will show me the artist(s) for the song, but, WMP has some unique fields, like Album Artist, and I really need to know what should i put %HERE% so i can see that info on Mp3Tag.