Some people may be wondering about DID-whatever codes, which should be treated as information for the release Notes field, not a cat#. Although I'd prefer to preface the code with the term "DADC master code", it's "Mastering LabelCode" that seems to have some traction on Discogs. I don't know where that term originates.
Anyway I'm reposting this from another forum that isn't publicly accessible so that it can be referred to as needed:
DID_ codes are the numbers used by Sony's manufacturing company, Digital Audio Disc Corporation, to identify the master copies of CDs duplicated in their pressing plants. DADC has used a number of different DID_ code series over the years:
* DIDC - Classical recordings released on Sony-d record labels.
* DIDP - Popular (i.e., non-classical) recordings released on Sony-d record labels.
* DIDX - Recordings pressed by DADC by released on non-Sony-d record labels.
* DIDY - Recordings pressed by the US division of DADC for the Columbia House Record Club.
* DIDZ - Recordings released on WEA Japan. (This code was only used from 1983 to 1985.)
A DIDX code on a release doesn't necessarily mean that copy of the release was actually pressed by DADC. As more CD pressing plants opened around the world, the record labels would often have other manufacturers press later runs of releases originally manufactured by DADC, but wouldn't necessarily remove the DADC mastering code from the CD's packaging. In some cases the DIDX codes also appear in the matrix codes of CDs manufactured by other companies.
The CSIG code that appears on some 3" CD singles may also be a DADC-assigned mastering ID, making it a close cousin of the DID_ codes.
