The CD ReWritable (CD-RW) system gives the opportunity to write, erase, overwrite and read CD information. The recorded CD‑RW disc has a lower reflectivity than a “Red Book compatible” disc, so it must be played back on “CD-RW enabled CD‑players”. A CD‑RW enabled CD‑player can read out CD‑RW discs described in this document, as well as CD‑R and conventional CD discs. The CD‑RW format gives the possibility for both Audio and Data recording.
In the CD‑RW system the disc contains a recording material which shows a reflection decrease due to writing, a reflection increase due to erase, and a reflection decrease or increase due to overwriting. The CD‑RW disc has a lower reflectivity in comparison with conventional CD discs, but satisfies almost all the remaining specifications as written in the chapter DISC SPECIFICATION of the Red Book. The CD‑RW disc contains a wobbled pre‑groove for tracking, CLV speed control and timing purposes. Recording takes place in the groove. The CD-RW system is described in the Orange Book, Part III. Volume 1 describes the 1-4x disc type; Volume 2 describes the 4-10x (High Speed) type and Volume 3 defines two types of Ultra Speed CD-RW discs:
- US24, an 8x-24x disc type that is compatible with Orange Book, Part III, Volume 3, Version 1.0.
- US32, an 8x-32x disc type that is write-incompatible with version 1.0. A new logo shall be used for US32 discs only.