DIDX numbers hide on the disc hub (the clear inner ring) and under the barcode. Catalog numbers live on the spine.
The numbers printed on every CD
Books have ISBNs; CDs have a small pile of identifiers that most tools ignore:
- DIDX numbers (“DIDX-2113”) — Sony’s disc-master ID, molded into the hub ring of the disc itself and often printed under the barcode. When a disc has lost its case, this is frequently the only identifier left.
- Catalog numbers (“CK 40999”) — the label’s own number on the spine and disc face.
- Barcodes (UPC/EAN) — when you have the case, this is the strongest match.
- Club numbers (“D 100462”) — BMG / Columbia House music-club pressings carry their own D-prefixed numbers that standard barcode scanners return nothing for. Coverage for these in open databases is thin; we’re building a fuller resolver for exactly this gap, and the miss card points you to the best manual search meanwhile.
Who this is for
Anyone sorting discs at scale: estate cleanouts, thrift hauls, media resellers, and donors deciding what’s worth passing along. Type the number, get artist and album, copy, and search your marketplace of choice — the same ten-key workflow as our LCCN Lookup for pre-ISBN books. Results come from the open MusicBrainz database; it’s an identification tool, not an appraisal.