I have seen some related discussion in the forum archives, but I'm not sure of its final resolution. So I thought I'd go ahead an make this suggestion for a useful future upgrade:
In the extended tag frame list, include the 4-character Frame ID (TYER, TALB, etc.) with each frame listing. I know this might seem a bit redundant, since you have a table on your web site that maps your frame names to the Frame IDs. But I often use mp3Tag to read/edit tags created elsewhere, and the 4-char Frame ID is a universal identifier. If I could see it in your listing, I wouldn't have to be comparing your naming scheme against someone else's, and then someone else's, and so on.
So it would be very convenient to see the Frame ID in front of the frame name and contents:
TCON GENRE Folk
TXXX LOCATION My upstairs media library
TIT1 CONTENTGROUP Beach Music
I think this might help a lot of us who are juggling various apps (like jukeboxes) that make modifications to the tags.
Thanks for considering this.
BTW - mp3Gain is an extremely useful program, and I very much appreciate having it in my toolbox.