I am trying to enumerate the complete list of replaygain tag formats used in MP3 files that produced by various encoders.

So far I have the following list:

mp3gain: APEv2
foobar: ID3v2 'TXXX'
LAME: LAME tag

I haven't found any applications that write the proposed standard 'RGAD' ID3v2 tag, although it appears that MAD and other players can read it.

Is anyone aware of any application or encoder that writes ID3v2 RGAD tags?

Thanks for the help!

Dave

I can't help you on this, I just want to say that I'd appreciate it if there was a definitive standard.