The Chicago Manual of Style is the venerable, time-tested guide to style, usage, and grammar in an accessible online format. It is the indispensable reference for writers, editors, proofreaders, indexers, copywriters, designers, and publishers, informing the editorial canon with sound, definitive advice. Its 17 editions have prescribed writing and citation styles widely used in publishing. It is one of the most widely used and respected style guides in the United States.