I want to be able to use the subtitle tag (TT3/TIT3) as a source for renaming files. (Podcasts from NPR put the time and date of the newscast in the subtitle field.) I checked the id3.py source to see if I could grasp how to add that. I see that there is a defined TT3/TIT3 class for this purpose but it never gets referenced. Would this be easy to add?