a book containing rules of usage in typography, punctuation, etc., employed by printers, editors, and writers.
a book featuring styles, fashions, or the rules of style.
The AP has now responded by banning the phrase from its stylebook.
The Stylebook would appear to be as uncomfortable with the nouveau as Astor and McAllister were.
I have at last got some business with you, and business letters are written by the stylebook.