Apostrophes are not used before the s in plural nouns.
The apostrophe is used in various ways:
Note: dos and don'ts, which should not have an apostrophe before the s in each word.
Contracted forms affect style. UCAS often uses contractions to indicate a conversational style.
The most common way to form a possessive is to add 's to the noun:
Plural nouns that do not end in s take 's in the possessive:
For nouns ending in s, add an apostrophe in all cases.