Catalog Number

目录编号 (Catalog Number, also written as Catalogue Number) is an internal identification number assigned to a recording record label, publisher, or manufacturer for a release. It has been used since the early days of commercial phonograph cylinders and records for cataloging, ordering, inventory, and sales, and is typically printed on the record label, the disc surface, the spine of the sleeve, and the back cover. When combined with the name of the record label, the 目录编号 can identify a specific release within its numbering system.

The number may consist of digits only, or it may include a letter prefix, format code, region code, price series, or edition suffix. Vinyl, CD, cassette, and digital versions of the same album often use different numbers, and releases in different regions may also be assigned separate numbers; box sets may have both a set number and individual disc numbers. The meaning of format codes within a string is defined by the specific record label; a company’s `-2` or `CD` conventions cannot be automatically applied to other record labels. 目录编号 is not a globally unique standard. Different record label entries may use the same string, and the same record label entry may also appear multiple times due to historical mergers, numbering restarts, or data entry errors. Co-releases may list two or more numbers side by side, and different parts of the packaging may also feature order numbers, price codes, master numbers, and manufacturing codes; only by considering the label signature and layout context can one determine which one is the catalog number.

It identifies a release or version of a product, not an individual recording. Multiple tracks may share a single album catalog number, while each recording may have its own ISRC; the GTIN in a barcode refers to a retail trade item and is typically used by the broader supply chain. The three may sometimes share some digits, but there is no inherent conversion relationship between them.

Reissues may retain the old catalog number or be assigned a new one. Retaining the old number does not prove that the pressing, master, packaging, and release dates are exactly the same, nor does a new number necessarily indicate a change in the audio content. Identifying specific editions usually requires examining the barcode, copyright line, manufacturing information, matrix numbers, and inner sleeve engravings in combination.