Using Apostrophes to Form Plurals
8.7.5 Using Apostrophes to Form Plurals
Do not use an apostrophe to indicate the plural of a name. Do not use an apostrophe in the name of an organization in which the qualifying term is used as an adjective or an attributive rather than a possessive. Of course, always follow the official name.
The Chicago Cubs
state parks rangers
Rainbow Babies Hospital
He uses too many and's.
The manuscript editor was mindful of the list of do’s and don't's.
Mind your p’s and q's.
There are 9 +’s on the page.
Do not use an apostrophe to form the plural of an all-capital abbreviation or of numerals (including years). (See also 9.5, Plurals, Abbreviations.)
His 1’s looked like 7's.
a woman in her 40s
during the late 1990s