What is the proper way to abrevieate "purchase orders"?

At work I deal with purchase orders a lot, and refer to them in emails all the time. Generally, the term PO is used instead of writing (or saying) the whole term “purchase order”.

Now, this is probably a dumb question, but how should I type the plural of “PO”? I’ve seen a lot of people use “PO’s”, but of course the 's should really represent ownership and not plural. I’ve also seen people use “POS”, but that looks like something completely different to me, and “POs” looks strange to me as well. So, is there any right way to spell this?

The context of these emails is pretty informal, typically just questions shot between people or whatever. To be honest, the grammar/spelling isn’t always perfect in these emails, and I’m more just curious about this than actually worried about making a mistake.

I used to work on a purchase order system with lots of big companies. It is PO and we always wrote PO’s as plural although I am not sure how correct that is formally speaking.

I don’t really see what’s wrong with “POs”. That’s what I’d use.

But I do agree that “POS” (all caps) is bad and potentially misleading.

POS is Point of Sale which is very different especially in a retail company.

I alway use “POs”. Oh, and I thought “POS” stood for “Piece of S***”

You think this is a headache… I’m currently working on some software that deals with POs and translating it is a pain. A lot of languages don’t use a shortened form so nothing fits.

I’m in the same boat at work. I use POs for purchase orders. POS is Point of Sale, which is also used within our company.

The use of the apostrophe is a style choice; there is no concrete “right” or “wrong.” Use either POs or PO’s as you wish. However, “POS” would definitely be wrong.

The grammar Nazi in my shudders at this. The apostrophe implies either possession or contraction, and neither of those applies here. While pretty much everyone would get the drift, this is not at all grammatically correct.

And they wonder why English is such a tough language to learn. . . :dubious:

It’s not really a matter of grammar; it’s a matter of spelling. And Scarlett67 has it right. Either one is right; just be consistent.

According to the Chicago Manual of Style:

Bolding mine.

The question is whether “POs” is felt to be confusing or not. Since POS is a frequent abbreviation in business contexts, probably in this case “PO’s” should be preferred. There is nothing incorrect about it.

I’m not talking about adding the apostrophe anytime you want to make a plural. Some styles allow it when omitting it might cause confusion, such as the plural of a single letter, or the “do” in “do’s and don’ts” (which always looks weird no matter how you style it).

I’d say “PO’s” falls into this category, and wouldn’t be uncomfortable styling it either way. (Though Chicago would lean toward omitting it, if an author preferred to keep it I would be OK with that.)

On preview: Colibri, is that from the 14th or 15th edition? (I can’t be arsed to dig out my copy of 14.) 15 has only the examples of Ph.D.'s and M.A.'s and x’s and y’s at para. 7.16; it doesn’t mention general confusion (although Amy Einsohn’s The Copyeditor’s Handbook [published before 15 came out] does).

While I agree that the apostrophe should be eschewed unless it’s necessary to avoid confusion, the NYTimes uses such an apostrophe consistently.

If your company is Enron, I suppose you should just spell it out and say “Probation Officers”.

or the plural for an abbreviation. Maybe you missed that day, or maybe your schooling omitted it (since it doesn’t seem to be universal), but it’s a longstanding and fairly widespread practice.

Really? The plural of an abbreviation. I have never seen anything authoritative advocate that use of an apostrophe. Can you point me to a style guide that advocates this use?

Apparently the Chicago Manual of Style, as mentioned by Colibri in post #10, and whatever the New York Times uses, as observed by lissener in post #12.

I say either “P.O.s” or “PO’s”

The apostrophe could account for the contraction of “Order”.

I think it’s safe to say the apostrophe indicates “this letter S is forming a plural, and is not part of the abbreviation.” As mentioned above, there is such a thing as a PO, and there is such a thing as a POS. Likewise, there is such thing as a TV, and there is such a thing as a TVS (thermal vacuum switch). Now, often the apostrophe is not truly necessary, either due to context (it’s extremely unlikely that someone dealing with televisions is also dealing with thermal vacuum switches) or upper/lower case usage (TVs is plural of TV, TVS is singular of TVS). But there might be cases where the apostrophe adds clarity.

Then, of course, there’s the problem of possessives - “That TV’s picture is really clear.” Hence it’s not surprising that there isn’t universal and consistent application of either form. Which brings us back to the real, if less than totally satisfying answer: either way is acceptable, neither way is incorrect, but in certain specific cases one way might be clearer.

FWIW, the standard at my work is to pluralize acronyms by adding a lower case “s”. So it would be POs, TVs, GRAs, etc. It’s a government job, so there’s a full page of explaination on the master acronym list, which is about 100 pages long.

It’s the 13th Edition, actually, section 6.10, p. 160. I probably should update one of these decades. :slight_smile: However, I am not aware that the convention has changed significantly.

I also would in general not use an apostrophe to make a plural UNLESS confusion is likely. In the previous section, 6.9 in my edition, Chicago indicates this is the preferred method for letters used as words, acronyms, etc. However, to prevent confusion, using an apostrophe is an accepted practice by major style manuals. (Certainly Chicago style, and I assume the NY Times uses either AP style or their own house style.)

Chicago style would make the first example “P.O.'s.” If you are using the apostrophe to indicate a contraction than the second example should be “P’O’s”; however, I have never seen that done and I doubt any style manual would accept it.

To be clear: although an apostrophe is typically used to indicate a contraction or a possessive, those are not its only uses. It can also be used, quite correctly, to indicate other spelling conventions or for clarity.