How to pluralise acronyms?

How to pluralise acronyms?

Lisa asks: How to pluralise acronyms when we are taught that plurals do not need an apostrophe, but to not add an apostrophe could lead to a whole new unintended acronym? 

Turns out it's a bit of a touchy subject...but then, I suppose, when is apostrophe usage not?

The blog post I wrote on apostrophes does not cover all usage. As well as indicating possession (Lisa's question) and omission of letters (isn't it?), we use apostrophes to show plural letters (Mind your p's and q's) and plural words (But me no but's, If if's and and's were pots and pans there'd be no work for tinkers).

But your question was about acronyms. Some say as long as it doesn't cause problems with understanding it's just a question of house style, as with years (1980's or 1980s). Some say it's a difference between American and British English -  Americans using apostrophes in plural acronyms, Brits not.

I think if clarity isn't compromised (e.g. MP's rigging election - just one or all of them?) it's okay to choose either.

Hope that helps!