Let's try avoiding being pedants. Human language is quite squishy and imprecise anyways.

Agreed. Whether or not you think grammar matters, bringing it up is destructive to the conversation this is meant to start.

As long as the style is consistent, it doesn't really matter.

The general newspaper style is acronyms with periods use apostrophe to separate period from s. Therefore M.D.'s and Ph.D.'s are plural. Where period is not used in the acronym, the apostrophe is not used, so CPU not C.P.U., therefore it's CPUs. Anyway, it's just a convention, the key is consistency.

Is this mentioned in any particular newspaper style guide that a general member of the public can get their hands on? Like the AP style guide for instance?

Using an apostrophe is the technically correct way to pluralize acronyms.

> Using an apostrophe is the technically correct way to pluralize acronyms.

No, it's not the “technically correct way”. It's true that some style guides recommend something like this (but always, AFAIK, more limited); e.g., the New York Times style (and Chicago style) uses apostrophes for plurals of abbreviatiins formed with capital letters and periods, and plurals of single letters. [0] AP, on the other hand, only uses apostrophes for plurals of single letters, but not for abbreviations/initialisms/acronyms. Most British styles I've seen don't use apostrophes for plurals at all, IIRC.

[0] https://afterdeadline.blogs.nytimes.com/2010/04/13/faqs-on-s...

How do you distinguish between plural and ownership if you use ‘s for both?

It's not uncommon for natural languages to have homonyms, so people are used to deal with them. The context allows deciding which is the correct meaning.

I’d love a reference for this convention.

Says whom?

Pretty common in our industry to use apostrophes after an acronym to make it plural. An example is VM's and VMS are two different things. When you get lazy and do vm's and vms you can not always be sure, I have even written an email where I stated "we need multiple VMS VM's".