Plurals of Abbreviations
I've read some articles on that topic, but I still have some questions. I would really appreciate your assistance in this regard.
As I understand, these plurals are formed by adding "s" (which is an ordinary way of pluralizing), and normally, we should try to avoid using an apostrophe. That's clear for me and it works perfectly for ATMs, PCs, DVDs etc. But what about those initialisms that end with "s"? CDS, for example (=Credit Default Swap). Is it correct to write CDSs for "swaps"? If yes, then how do you pronounce it? [si - di - siz] / [si - di - es] / ??? I tried to find an example on Youtube but people seem to be coping extremely well with avoiding this abbreviation (or they just say it as in a singular form so I'm unable to hear the difference). Anyway, I'm talking about the sentences in which it's absolutely necessary to use a plural form (e.g. "The number of CDSs has been increasing for several years").And what about those initialisms that ends with a vowel? IPO, for example. Is it [ai - pi - os] or [ai - pi - o(u)z]?
And the last question. Can we pluralize an initialism in which a noun stands for the first initial? (sorry, I don't know the right way to say it). I mean, it makes sense for those abbreviations that ends with a noun, e.g. "NESs" ("Native English Speaker"s) but it doesn't sound absolutely right for ones like "MOFs" (because the result looks more like "Ministry of Finance"s). Should I ignore it? Maybe I'm reading too much into it.
Sorry for such a long question. Any help would be very much appreciated.