The Standard Product Number is defined in the Record Industrial Standard (RIS) and assigned by the Recording Industry Association of Japan (RIAJ).
The Recording Industry Association of Japan (RIAJ) is an organization representing the Japanese music recording industry. It also defines the standard known as the Record Industrial Standard (RIS) (Japanese only).
RIS has 5 categories:
- RIS100~: Basic terminology
- RIS200~: Audio disc recording
- RIS300~: Audiotape recording
- RIS400~: Video recording
- RIS500~: System information
RIS204 (Audio CD Label Content and Format) (Japanese only) explains how to display the audio CD, including the Standard Product Number (規格品番), which is explained more in RIS502 (Recording Product Number) (Japanese only).
The format is defined as XXYZ-12345, where:
- XX: company code (2 digits)
- Y: media format code (1 digit)
- Z: genre code (1 digit, arbitrary by the company, usually to separate between labels or genre)
- 12345: serial number (5 digits)
The list of company code, media format code, and genre code is further referenced in RIS504 (Online Data Interchange Format for Master Data of Record Product), which is also listed in the Japanese Wikipedia (company code and media format code) and its English translation by user 'eeepi' on rateyourmusic.com.
For the codes mentioned in the question:
- Company code:
- NEC Interchannel → Interchannel → I.C. Avenue → Index Music → T.Y.Entertainment Inc. → DREAMUSIC Inc (FEEL MEE Label).
- Nest → Onkyo Entertainment Technology
- KI: KING RECORD CO., LTD.
- MM: Marine ENTERTAINMENT Inc.
- Media format code
- C: 12cm CD
- D: part of Digital Audio Tape → 8cm CD → part of downloadable single/album