ID3
From Hydrogenaudio Knowledgebase
ID3 is one of the oldest ways of storing metadata in MP3 files, and is only intended for MP3 files. There are two major versions.
ID3v1
This is a very basic tagging format. It's limited to the following fields:
- Song title
- Artist
- Album
- Year
- Comment
- Genre
- Album track (ID3v1.1)
ID3v2
ID3v2 is much more complicated than version 1, and all fields can be defined freely. It also supports embedding pictures and other data. Usually, a rewrite of the file is neccessary each time you update an ID3v2 field.