The Philips "Green Book" specifies the standard for interactive, multimedia compact discs designed for CD-i

CD-i

CD-i, or Compact Disc Interactive, is the name of an interactive multimedia CD player developed and marketed by Royal Philips Electronics N.V. CD-i also refers to the multimedia Compact Disc standard used by the CD-i console, also known as Green Book, which was developed by Philips and Sony...

 players http://www.licensing.philips.com/information/cd/video/documents146.html. This compact disc format is unusual, because it hides the initial tracks which contains the software and data files used by the CD-i players. It does this by omitting the tracks from the disc's Table of Contents. This causes audio CD

Red Book (audio CD standard)

Red Book is the standard for audio CDs . It is named after one of the Rainbow Books, a series of books that contain the technical specifications for all CD and CD-ROM formats.The first edition of the Red Book was released in 1980 by Philips and Sony; it was adopted by the Digital Audio Disc...

 players to skip the CD-i data tracks. This is different from the CD-i Ready

CD-i Ready

CD-i Ready is a compact disc format based on the CD-i format. CD-i format and CD-i Ready format use different techniques to get audio CD players to skip over the CD-i software and data. CD-i Ready places the software and data in the pregap of Track 1. Standard CD-i format places the software and...

 format, which puts CD-i software and data into the pregap of Track 1.