I'm sure that, as a big-time Tech Writer, you'll have no problem coming up with the plural of "octopus". What's that? Speak up. Ah, "octopi". Very good. But wrong. Completely wrong.
You can momentarily feel good that every online dictionary I queried agrees with you (and most throw in "octopuses" for good measure). Sorry, but there's no cigar in it for either you or any of the dictionary makers (increasingly hard to find someplace to smoke it, anyway).
Of course, we all know that a second declension Latin noun ending in "us" forms its plural by changing the "us" to an "i". Sure looks like a second declension Latin noun, doesn't it? However, it isn't. "Octopus" is actually derived from the Greek "oktopous" and forms its plural by changing the "pus" to "podes". That's right, chillun, the real plural is "octopodes" (oc-TOP-po-dees), a word you probably never even knew existed (and one that doesn't turn up in any online dictionary that I rummaged through). Seems to me, though, that if you're going to pretend to be erudite and use a foreign plural, you might as well use the right one.
So here you have a conundrum: do you use the correct word and have everyone think you're illiterate or do you use a word which you now know, thanks to my insensitive meddling, is incorrect? (Look, I'm not interested in irrelevancies like "Just when do you think I'm gonna use 'octopus' in one of my manuals?" This is my rant, not yours! We're talking Eternal Verities here. Besides, if you can't think of a way of introducing 'octopus' into a quick start guide, maybe the Evil Editing Police should get you in the middle of the night.)
Or maybe (just maybe) KISS will kick in (that's "Keep It Simple, Stupid", not a reference to Gene Simmons). Why not just say "octopuses"? It's a good, solid English formation, it's recognized by most dictionaries, and everyone (read: "the Poor Bewildered Customer") will know exactly what you're talking about.
As long as I've mentioned it, here's a question for you: what kind of a formation is KISS? An acronym, you say. Well, you're right. I'm sure you know an acronym when you see one: NATO, scuba, VIP, snafu, ASCII, ISO, html, ftp. Darn, now you screwed up. Some of them are and some of them aren't. Technically, to be an acronym, a word made up of initials has to have two characteristics: it must be able to be pronounced as a word and it must actually be pronounced as a word. Thus, NATO, scuba, snafu, ASCII, and ISO are all perfectly good acronyms. However, VIP, html, and ftp aren't. While you could pronounce VIP as "vip", no one does, so it isn't an acronym. While I have heard html pronounced as "huh-TIM-el", it was just someone trying to be funny (and succeeding, as I recall); it isn't an acronym either. Ok, ok, if you must know, words like that are called alphabetisms (and both are categorized as initialisms).
Speaking of pronunciation, the study of pronunciation is called orthoepy. While I'm sure you could have lived without knowing that, there's something unbelievably (and unintentionally) hilarious about the word. In one of the great ironies of the universe, there's no agreement on whether it's pronounced "OR-tho-epy" or "or-THO-epy". Sounds to me like someone forgot KISS Theory. Why not just call it "pronunciology" and have done with it?
Remember KISS. Unless you're trying to do something really cool (to keep yourself and the customer awake), Keep It Simple, Stupid! (And next time you see them, say hello to Gene and Ace for me.)