Most taggers dont use all the tagging capabilities the ID3 v2 tag has to offer, to the possible extent.
The AllFrames-tagger for Mp3files gives you the opportunity to write an unlimited amount of frames with any kind of content into the file- whatever you need to tell or show- you can tag it and read it back again.
You can for example:
Save ratings and song properties independantly from the use of a database.
assign an individual customer ID to the file
Add content such as info on artist, production, concerts etc.
Give your users the ability to create own frames and save their relevant information within the file.