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Codes and Identifiers

ASIN – Amazon Standard Identification Number

  • Used to identify products on Amazon.
  • 10-character base36 uppercase code.
  • All products (except books) start with "B".
  • Books use ISBNs in place of ASINs.
  • All ISBNs are valid ASINs.

Barcode

  • Used to identify general trade goods.
  • 8/12/13/14 digit code with the last digit being a check digit.
  • Begins with a 3 digit country code, sometimes denoting categories besides countries.
    • If a barcode begins with 450-459 it is most often a Japanese release or a Japanese edition of a release.

CatNo, Cat# – Catalog Number

  • Used to identify releases within (and usually between) music labels.
  • Usually consists of a label abbreviation and a product number.
  • Usually printed on the spine and back of CD cases.
  • Sometimes contains a code marking the release medium.
  • Sometimes ends with a number delimited by "-" or "~", denoting multiple sequential catalog numbers for one release.
  • Not unique across labels.
  • No standard format.

CDID – Compact Disc Identifier

  • Used to identify audio CDs based on the number of tracks and their lengths in order.
  • Track offsets and lengths cannot be deduced from the identifier without a lookup.
  • Conversion between variants is not possible.
  • CDID can be created from the CDTOC.
  • Variant examples for different services:
    • MusicBrainz 
      1
      t3HFsohhglnyq3wqMIcpyN6.GKo-
    • CUETools 
      1
      F1_BSfwmYSGkzPbV7jsW0Dt4ThY-
    • AccurateRip 
      1
      0008b189-0034479c-62079207
    • FreeDB / Gnudb 
      1
      62079207

CDTOC – Compact Disc Table of Contents

  • Used to identify audio CDs based on the number of tracks and their lengths in order.
  • Conversion between encodings is possible.
  • Measured in frames where:
    • 1 frame = 588 samples
    • 1 frame = 1 sector
    • 75 frames = 1 second
  • Encoding examples for different services:
    • MusicBrainz 
      1
      1 7 145536 150 21163 40383 58974 81737 101849 121145
    • CUETools 
      1
      0:21013:40233:58824:81587:101699:120995:145386
    • Gracenote 
      1
      150 21163 40383 58974 81737 101849 121145 145536
    • MCDI 
      1
      96+52AB+9DBF+E65E+13F49+18DD9+1D939+23880

IPI Base Number - Interested Parties Information Base Number

  • Used to identify a music rights holder (composer, lyricist or publisher).
  • Obtained from CISAC through a country's performing rights organization (PRO).
  • Formatted as "HNNNNNNNNNC" or "H-NNNNNNNNN-C":
    • "H" is the header.
    • "N" is an identification digit that makes up the identification number.
    • "C" is a check digit.

IPI Name Number - Interested Parties Information Name Number

  • Used to identify a name or pseudonym of a music rights holder (composer, lyricist or publisher).
  • Obtained from CISAC through a country's performing rights organization (PRO).
  • 11-digit number that may be prefixed with "0" for 9-digit and 10-digit numbers.

ISBN – International Standard Book Number

  • Used to identify books.
  • 10-digit code ending with a check digit.

ISNI - International Standard Name Identifier

  • Available at isni.oclc.org.
  • Used to identify anyone in a creative role.
  • 16-digit numeric code formatted as "NNNNNNNNNNNNNNNC" or "NNNN NNNN NNNN NNNC":
    • "N" is a digit.
    • "C" is a checksum digit or literal "X".

ISRC – International Standard Recording Code

  • Used to identify sound recordings.
  • 12-character alphanumeric uppercase code formatted as "CCXXXYYNNNNN" or "CC-XXX-YY-NNNNN":
    • "CC" is the country code.
    • "XXX" is the issuer code within the country.
    • "YY" is the last 2 digits of the year.
    • "NNNNN" is an identifier for the recording within the year.
  • Sometimes the "CC" part of the ISRC identifies a legal entity instead of a country:

ISWC - International Standard Work Code

  • Used to identify musical works and compositions.
  • 11-character alphanumeric uppercase code formatted as "T-XXX.XXX.XXX-C":
    • "T" is the type code, literal "T".
    • "XXXX" is the work identifier.
    • "C" is the check digit.

Label Code

  • 4-digit or 5-digit code prefixed with "LC-".
  • Used to identify music labels.

MBID - MusicBrainz Identifier

  • A 36 character UUID (e.g. b083288e-5d83-429f-a4d7-b73c95d82d02) identifying artist, recording, work, release, release group, label and other entities on MusicBrainz.
  • One entity can end up with multiple IDs when entities are merged.
  • These IDs are used in various projects as a universal identifier for entities across services.


Updated 2026-06-12