 In consequence, any copies of a disc made with a regular recorder will lack the ROM Mark data and will be unreadable on standard players.The Blu-ray Disc Association recommends but does not require that Blu-ray Disc drives be capable of reading standard DVDs and CDs, for backward compatibility.Most Blu-ray Disc players are capable of reading both CDs and DVDs; however, a few of the early Blu-ray Disc players released in 2006, such as the Sony BDP-S1, could play DVDs but not CDs.