Page 121 - Perfect English Grammar: The Indispensable Guide to Excellent Writing and Speaking

9.5 Pluralizing Acronyms and Initialisms

Acronyms and initialisms are usually made plural by adding -s.

■ CD-ROMs

■ FAQs
■ MVPs

However, some style guides prefer to use -’s: for initialisms: ATMs or ATM’s
MOUs or MOU’s RBIs or RBI’s RFPs or RFP’s VIPs or VIP’s Major news

organizations and style guides differ on this, and both styles are widespread. As
is always the case, use the method preferred by your organization, and be

consistent. My preferred style is to add just -s.
If your preferred style is to use periods in your initialisms, then the best

course of action to make them plural is without the apostrophe.

■ I.C.B.M.s

■ N.G.O.s