The Chicago Manual of Style Homepage to The Chicago Manual of Style Online. University of ChicagoFind it. Write it. Cite it. The Chicago Manual of Style Online 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. ¶ Over 1.5 million copies sold!