If you need to rename a large number of files in a directory accordingly to their ID3 description and a given "formula" (e.g. (%Track) %Artist - %Title). Do you have loads of MP3 files in a directory and need to write a single common piece of information into them (e.g. the interpret or the album name)? You can type it in there manually, but this won't make you very cheerful if the amount of files is large. And what about the diacritics removal - e.g. for an MP3 player? Using ID3 renamer, everything is a matter of a few mouse clicks.