Audacious

Audtool it a fantastic utility, but I wonder what ID3 tag version(s) does it support? I notice some of my tags work with audtool but others do not, so I am assuming some of my tags are not compatible versions.

As an example, I used mediainfo to validate there is a populated comment field on each of two different tags, but when entering in bash audtool --current-song-tuple-data comment
only one of the tags displays the comment field data, the other displays a blank return.

If it is a version compatibility issue, then I just need to know the correct version to write the tag(s) to.

This tag displyed the comment correctly in audtool:

@lpc123@archmain ~]$ mediainfo $(audtool --current-song-filename)
General
Complete name : /media/sdc2/michael_kiwanuka/love_and_hate/05_-_michael_kiwanuka_-_love_and_hate.mp3
Format : MPEG Audio
File size : 16.3 MiB
Duration : 7 min 7 s
Overall bit rate mode : Constant
Overall bit rate : 320 kb/s
Album : Love & Hate
Album/Performer : Michael Kiwanuka
Track name : Love & Hate
Track name/Position : 05
Grouping : 4
Performer : Michael Kiwanuka
Genre : 2010s BritPop
Original/Released date : 2016
Recorded date : 2016
Writing library : LAME3.99r
Comment : Michael Samuel Kiwanuka (born 3 May 1987) is an English soul musician who is signed to Communion Records.[1] He has been compared to Marvin Gaye, Curtis Mayfield, Bill Withers, Randy Newman, Terry Callier, and Otis Redding,[2] as well as Van Morrison and the Temptations.[3] In January 2012, he won the BBC's Sound of 2012 poll.
Songs-DB_Custom5 : 4
Songs-DB_Custom4 : 2010s
REPLAYGAIN_ALBUM_PEAK : 0.524725

Audio
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 3
Format settings : Joint stereo / MS Stereo
Duration : 7 min 7 s
Bit rate mode : Constant
Bit rate : 320 kb/s
Channel(s) : 2 channels
Sampling rate : 44.1 kHz
Frame rate : 38.281 FPS (1152 SPF)
Compression mode : Lossy
Replay gain : -8.36 dB
Replay gain peak : 0.999969
Stream size : 16.3 MiB (100%)
Writing library : LAME3.99r
Encoding settings : -m j -V 4 -q 3 -lowpass 20.5
MP3Gain, Min/Max : 053,206
MP3Gain, Undo : +004,+004,N
@

This one did not:

@[lpc123@archmain ~]$ mediainfo $(audtool --current-song-filename)
General
Complete name : /media/sdc2/grizzly_bear/shields/06_-_grizzly_bear_-_a_simple_answer.mp3
Format : MPEG Audio
File size : 9.48 MiB
Duration : 6 min 0 s
Overall bit rate mode : Variable
Overall bit rate : 220 kb/s
Album : Shields
Album/Performer : Grizzly Bear
Track name : A Simple Answer
Track name/Position : 06
Grouping : 1
Performer : Grizzly Bear
Genre : 2010s Indie
Recorded date : 2013
Writing library : LAME3.98r
Comment : Shields is the fourth studio album by American indie rock band Grizzly Bear, released on September 18, 2012 by Warp Records. Written and recorded following a six-month hiatus from band activities, the album was produced by bassist and multi-instrumentalist Chris Taylor, and preceded by the singles, "Sleeping Ute" and "Yet Again".
Rip date : 2013-11-12
Songs-DB_Custom3 : 1
Release type : Normal release
Songs-DB_Custom5 : 1
Source : Deluxe Edition

Audio
Format : MPEG Audio
Format version : Version 1
Format profile : Layer 3
Format settings : Joint stereo / MS Stereo
Duration : 6 min 0 s
Bit rate mode : Variable
Bit rate : 220 kb/s
Minimum bit rate : 32.0 kb/s
Channel(s) : 2 channels
Sampling rate : 44.1 kHz
Frame rate : 38.281 FPS (1152 SPF)
Compression mode : Lossy
Replay gain : -9.00 dB
Replay gain peak : 0.437388
Stream size : 9.48 MiB (100%)
Writing library : LAME3.98r
Encoding settings : -m j -V 0 -q 0 -lowpass 19.5 --vbr-new -b 32
Language : English
MP3Gain, Min/Max : 134,250
MP3Gain, Undo : +005,+005,N
@