%contentgroup% no longer displays in iTunes

Has anyone had this problem of late.

I've only just discovered that it no longer shows up in iTunes.

Wrting to the %contentgroup% TAG is no longer viable.

Using iTunes and mp3tag 2.79.

Looks like they discontinued File tag support for the existing Grouping field:

Now I've nowhere to write the PUBLISHERs info as I use the COMMENT field exclusively for songs key and mixed in key info.

If you write your tags to the %contentgroup% field then it displays in the work field in itunes (the only way currently to display this is by showing the column for it. And vise-Versa, if you write info to the work field it is now mapped to the %contentgroup% one.
Read more here:

see e.g. here: /t/18175/1

I got it figured out anyway from doing some googling. Check EDIT2 I had in first first.