Associated Press or, AP style, is used by reporters, editors and others as a guide for grammar, punctuation and principles and practices of reporting. The organization's AP Stylebook is updated annually by the Associated Press editors, usually in June.
Although some publications use a different style guide, the AP Stylebook is considered a newspaper industry standard and is also used by broadcasters, magazines and public relations professionals. It includes an alphabetical listing with guides to capitalization, abbreviation, spelling, numerals and usage.
AP Style Resources: