apostrophe plurals
Whether an apostrophe marks an ordinary plural.
Do not use an apostrophe to make a regular noun plural: forms, memos, the Joneses. An apostrophe plus s may mark the plural of a single letter when the plain s would be unclear: Mind your p’s and q’s. Dot the i’s. For capital letters and numerals, prefer no apostrophe: three As, the 1990s. Do not write CD’s, photo’s, or 1990’s as plurals.
Examples
UseBring two IDs.
AvoidBring two ID’s.
UseCross the t’s.
AvoidThe memo’s are on the desk.