/blü bu̇k/
n. 1. Informal name for one of the three standard references on the page-layout and graphics-control language PostScript ('PostScript Language Tutorial and Cookbook', Adobe Systems, Addison-Wesley 1985, QA76.73.P67P68, ISBN 0-201-10179-3); the other two official guides are known as the Green Book and Red Book.
2. Informal name for one of the three standard references on Smalltalk: 'Smalltalk-80: The Language and its Implementation', David Robson, Addison-Wesley 1983, QA76.8.S635G64, ISBN 0-201-11371-63 (this is also associated with green and red books).
3. Any of the 1988 standards issued by the CCITT's ninth plenary assembly. Until now, they have changed color each review cycle (1984 was Red Book, 1992 would be Green Book); however, it is rumored that this convention is going to be dropped before 1992. These include, among other things, the X.400 email spec and the Group 1 through 4 fax standards.
See also book titles.