NAB conforms with The Associated Press Stylebook. The AP Stylebook is accessible online at apstylebook.com. If you have any questions, please contact the Marketing department.

• Spell out numerals that start a sentence: If the result is awkward, recast the sentence. Example: Twenty-seven detainees were released yesterday. Yesterday, 993 freshmen entered the college.
• The one exception to this rule is in a sentence that begins with a calendar year. Example: 1938 was a turbulent year for Leon.
• Use Roman numerals for wars, monarchs and popes: Example: World War II, King George VI, Pope John XXIII.
• For large numbers, use a hyphen to connect a word ending in y to another word: Example: twenty-one, one hundred forty-three, seventy-six thousand five hundred eighty-seven.
• Do not use commas between other separate words that are part of one number. Example: one thousand one hundred fifty-five.
• Spell out casual expressions: Example: A thousand times no!
• For proper names, use words or numerals according to an organization’s practice: Examples: 3M, Twentieth Century Fund, Big Ten.