This document provides 14 rules for using commas in writing. Some key rules include: using commas in a series of 3 or more items, between the day and year in dates, between the city and state in addresses, to set off introductory phrases, in compound sentences joined by FANBOYS conjunctions, and to separate phrases and clauses from the rest of the sentence. Mastering these 14 comma rules can help a writer improve their skills.