Help adding multiple comments to MP3

I need help adding more than 1 comment to a MP3 file. I understand an MP3 can have multiple comments, but I don't know how to add extra ones and have them actually be "comments."

The reason I need this is I want to be able to send custom fields over a Shoutcast stream, but that only supports these fields: http://wiki.winamp.com/wiki/SHOUTcast_XML_...a_Specification. However, it does support sending multiple comments which would appear as:

This is a comment
.
This is another comment

So how would I correctly add a "whatever" comment and then a "more" comment?

To add more than one comment field, proceed in one of the following ways:

Open the extended tags dialogue (Alt-T)
Click the "new" button next to the field list
Select as field "Comment" and enter the text.
You will see one more comment field in the field list.

Or:
Enter a text like "whatever\\more" in the comment field input box.
The \\ tells Mp3tag to create a multivalue-field for COMMENT. You will have 2 comment fields after saving. You can check that in the extended tags dialogue.

I see a problem when you try to create an export for such a field. if you use a simple %COMMENT% for output then you get the data from the first field of the type comment.
There is no for...next loop to step through the instances of the multi-value fields.
So you would have to think of a way to first join the multi-value fields with a unique separator and then replace that with whatever text you want to see in the export.

Is it possible to add a content descriptor to each comment? I think the "id" that is shown on the output by Shoutcast is actually the content descriptor that a comment can have (see http://id3.org/id3v2.3.0#Comments).

???
/t/10272/1
/t/3785/1

DD.20170209.2033.CET

I think that any tag field with a name that starts with COMMENT is treated as COMMENT, e.g. COMMENT ITUNNORM.
So perhaps COMMENT SHOUTCAST works.