If you are referring to Composer for Classical music than answer would be that tags are cross-linked Change Track Type to Music you can see equivalent of Composer.

For composer you want "itm.Author". There's a full list on the wiki... http://www.mediamonkey.com/wiki/index.php/SDBSongData

The "Auto-Tag from Filename" function is very useful but not all the tags can be used.
But the scripts can help; e. g. if I want to load the "Lyricist" tag I use the "Auto-Tag from Filename" putting the Lyricist name into the "Publisher" tag (which is not useful for me) and then using a script I can copy Publisher into Lyricist.
Unfortunately I cannot do the same with the tag "Composer" that cannot be used, with this name, in the script (I tried writing "itm.Composer").
Is it possible to have a list of all the tags that can be referenced in a script ?

Regards, Daniele