The Red Book audio specification, except for a simple "anti-copy" statement in the subcode, does not include any copy protection mechanism. Known at least as early as 2001, attempts were made by record companies to market "copy-protected" non-standard compact discs, which cannot be ripped, or copied, to hard drives or easily converted to MP3s. One major drawback to these copy-protected discs is that most will not play on either computer CD-ROM drives or some standalone CD players that use CD-ROM mechanisms. Philips has stated that such discs are not permitted to bear the trademarked Compact Disc Digital Audio logo because they violate the Red Book specifications. Numerous copy-protection systems have been countered by readily available, often free, software. COUNT 3
QSN1 When did record companies first attempt to protect their CDs from copying? ANS1 2001 QSN2 Who said that protected CDs are not allowed to carry the CDDA logo? ANS2 Philips QSN3 Where does the Red Book mention copy protection? ANS3 in the subcode