The 'Content type', which ID3v1 was stored as a one byte numeric
value only, is now a string. You may use one or several of the ID3v1
types as numerical strings, or, since the category list would be
impossible to maintain with accurate and up to date categories,
define your own. Example: "21" $00 "Eurodisco"
$00
You may also use any of the following keywords:
RX Remix
CR Cover
@author Eric Farng
@version $Revision: 1.4 $