(I'm asking this question here, rather than on the Receiver BBS, because I figure that more people will read it).

Last night, I resumed hacking on my Replacement Rio Server. It'll be written in pure C#. I'm currently hacking on the ID3 import code.

One of the tracks I've got (tagged with ID3v2.3.0) has what appears to be a 'CM1' tag in it. It appears to contain text.

Any idea what it is? According to my understanding of the docs, it's not a legal frame.