Blue Book (CD standard)

[1] The format was created as a way to solve the problem of mixed mode CDs, which were not properly supported by many CD players.

The second session will only be used by computer systems equipped with a CD-ROM drive, or by special “Enhanced CD players”.

[2] The technology was originally developed by Albhy Galuten who, along with Ty Roberts brought the idea to the major record labels where it was built into commercial releases.

There were other technologies that solved the same problem, but they were not compatible with many existing CD players and so this approach was brought to Sony and Philips where it was written into the Blue Book standard.

The term "enhanced CD" is also an umbrella term and a certification mark used to refer to different CD formats that support audio and data content, including mixed mode CDs, CD-i and CD-i Ready.