=== RGAD - Replay Gain Adjustment (class 3) ===

Specified at [[http://wiki.hydrogenaudio.org/index.php?title=ReplayGain_specification#ID3v2  | Hydrogen Audio ]]
{{{
	<Header for 'Replay Gain Adjustment', ID: "RGAD">
	Peak Amplitude				$xx $xx $xx $xx
	Radio Replay Gain Adjustment		$xx $xx
	Audiophile Replay Gain Adjustment	$xx $xx

	Header consists of:
	Frame ID		$52 $47 $41 $44	= "RGAD"
	Size			$00 $00 $00 $08
	Flags			$40 $00		(%01000000 %00000000)

        In the RGAD frame, the flags state that the frame should be preserved if the ID3v2 
        tag is altered, but discarded if the audio data is altered.
}}}

This is not widely supported and I think it has been superseded by RVA2 in ID3v2.4 (and the XRVA tag for 2.3 compatibility).