The Chicago Manual of Style
The Chicago Manual of Style (CMS) is a highly regarded style guide for American English, dealing with questions of style, manuscript preparation, and, to a lesser degree, usage. (Note that in the publications world, style means punctuation, italicization, bolding, capitalization, tables, and so forth, and not prose style.)
The CMS is commonly used by publishers and editors as a last resort for questions of proper presentation of text.
It is published by the University of Chicago Press. The first edition was published by the University in 1906 under the title A Manual of Style. As of 2003, it is in its 15th edition. There is also a web-based version.
- Chicago Manual of Style Official website