APE key

An APE tag item key is a key for accessing special meta-information in an audio file.

APE tag item keys can have a length of 2 (including) up to 255 (including) characters in the range from 0x20 (Space) until 0x7E (Tilde).

Typical keys should have a length of 2 ... 16 characters using the following characters:
Space (0x20), Slash (0x2F), Digits (0x30...0x39), Letters (0x41...0x5A, 0x61...0x7A).

Values can contain binary data, a value or a list of values. See here.
List of values can be mixed, i.e. contain UTF-8 strings and external references
beginning with file://..., http://www..., ftp://ftp....

Not allowed are the following keys: ID3, TAG, OggS and MP+.

Currently the following keys are defined:

Key	Meaning	Recommended format of value
Title	Music Piece Title Music Work	UTF-8 string
Subtitle	Title when TITLE contains the work or additional sub title	UTF-8 string
Artist	Performing artist List of Performing Artists	UTF-8 string List of UTF-8 strings
Album	Album name	UTF-8 string
Debut album	Debut album name	UTF-8 string
Publisher	Record label or publisher	UTF-8 string
Conductor	Conductor	UTF-8 string
Track	Track Number Track Number/Total Tracks Number	Integer Integer/Integer
Composer	Name of the original composer Name of the original arranger	UTF-8 string List of UTF-8 strings
Comment	User comment(s)	UTF-8 string List of UTF-8 strings Link List of Links
Copyright	Copyright holder	UTF-8 string List of UTF-8 strings
Publicationright	Publication right holder	UTF-8 string List of UTF-8 strings
File	File location	Link List of Links
EAN/UPC	EAN-13/UPC-A bar code identifier	12 or 13 digit Integer
ISBN	ISBN number with check digit	9 digit number with a check digit (0...9 or X)
Catalog	Catalog number	sometimes in the EAN/UPC, often some letters followed by some numbers
LC	Label Code	LC + 4 or 5 digit Integer
Year *	Release date	Date
Record Date	Record date	Date
Record Location	Record location(s)	UTF-8 string List of UTF-8 strings
Genre **	Genre(s)	UTF-8 string List of UTF-8 strings
Media	Source Source Media Number/Total Media Number Source Time	Media Media Integer/Integer Media Time
Index	Indexes for quick access	Index Time List of Index Times
Related	Location of related information	Link List of Links
ISRC	International Standard Recording Number	ASCII String
Abstract	Abstract	Link
Language	Used Language(s) for music/spoken words	UTF-8 string List of UTF-8 strings
Bibliography	Bibliography/Discography	Link
Introplay	Characteric part of piece for intro playing	Index Time Range
Dummy	Place holder	Zero data

*This key name is used to be upward compatible.

**Genre keywords should be normally English terms. A native language supporting plugin can translate common expression to the local language and vice versa when storing the genre in the file.