e/Purple Book

Information
has gloss	eng: Purple Book is the informal name for Sony and Philips' specification document for the double-density Compact Disc (DDCD) format. The Purple Book format allows a CD to hold 1.3 Gigabytes by narrowing the track pitch from 1.6 to 1.1 micrometre s, and shortening the minimum pit length from 0.833 to 0.623 micrometres.
lexicalization	eng: Purple Book
instance of	e/Rainbow Books