The document provides rules for the proper use of apostrophes in possessives and contractions. It discusses using apostrophes with singular and plural nouns, as well as proper nouns ending in s. It also covers the differences between it's, its, they're, their, and there. The key points are: use 's to make a singular noun possessive; use s' for a plural noun possessive; use ' after a proper noun ending in s. Contractions like it's mean "it is" while its is possessive.