The Comments edit panel is used to display and edit all comments for the current file selection. The comments displayed on the Info panel is the default comment. The default comment is the comment which has an empty description field.
The table displays the comments found in the currently selected files.
A comment has two fields other than the actual text field. The first is the Description field which is a short description used to differentiate multiple comments in the same file. This field is intended to be unique amongst all the comments in a single file. The second field is a three character language code which describes the language of the comment. The field will display the default language code you set in Settings-Audio-ID3 Specific. You can leave the field empty to use your default.
All editing and manipulation is done via the context menu and is described here.
For compatibility between audio formats you should use User Defined Text Information Items (UDTIs) as an alternative wherever possible.