GPO

Published since 1894 as a guide to the style and form of Federal Government printing, the U.S. Government Printing Office Style Manual has become a major reference source for professionals involved in the field of Federal printing and publishing. Designed to achieve uniform word and type treatment and economy of word use in the form and style of Government printing. 

Also cited as GPO Style Manual, it is issued by the Public Printer under authority of Section 1105 of Title 44, United States Code. The GPO Style Manual is a must-have for writers and editors of Government publications. 2008 Edition (Paperback).

NEW in the latest (2008) edition of the U.S. Government Printing Office Style Manual:

    A more contemporary and readable format
    URLs for further information
    An expanded glossary of computer terms
    New and updated entries in the Useful Tables chapter
    An updated list of foreign country information
    A totally revamped Capitalization chapter
    A new section on GPO's online initiatives
    Inclusion of many suggestions from users

...and much more.

You can order the Style Manual in paperback, hardback, and CD-ROM versions.