This posting was to have been about style sheets, and its opening sentence was to have been the following:

Companies that produce documentation intended for the public typically have a “house style” defined by a set of “dos and don’ts” that writers are expected to follow in the performance of their craft.

The question of whether the text from “Companies” to “craft.” here should have been enclosed in (double) quotation marks with “house style” and “dos and don’ts” changed accordingly to ‘house style’ and ‘dos and don’ts’ is a rabbit hole we will deftly sidestep lest we encounter the Bunny of Self-Referential Embedding in its lair. (What was that masked first sentence anyway?) Like the centipede rendered immobile when asked how it knows in what order to lower and raise its feet, I balked at the spelling of “dos and don’ts.” Is “dos and don’ts” a “do” or a “don’t?” How about “do’s and don’ts?” Or “does” (like “tomatoes”)? “Don’t’s?” If you look at any one of the possibilities long enough, it will look wrong (especially when it’s enclosed in quotation marks, most especially in single quotation marks, as in: “This style sheet seems to consist of fewer ‘do’s’ than ‘don’t’s.’”)

So, leery of the nonjudgmental Internet’s inevitable cornucopia of choices and not having immediate recourse to Mom, who anyway would have told me to look it up myself, I first checked a couple of dictionaries (The American Heritage Dictionary [fifth ed., 2011] and (OK, I did visit the Internet) and then went on to consult the somewhat older hardbound Gang of Three—Prentice-Hall’s Words into Type [third ed., 1974], the United States Government Printing Office’s Style Manual [1984], and The Chicago Manual of Style [15th ed., 2003]—hoping for an authoritative last word.

The AHD and Merriam-Webster are pretty much in agreement about the plural of the noun(s) do. Here’s what the AHD has to say:


Compare Merriam-Webster’s “A command or entreaty to do something <a list of dos and don’ts>.” The dawdler, distracted by do2 and do3, might wonder whether the first measure of “Yankee Doodle” should be two dos followed by a re followed by a mi, or should that be two does? (Both dictionaries are mute on the subject. So, incidentally, is the OED, which doesn’t give a preferred plural form for any of its do entries, though it does offer adoes and ados as alternative plurals for ado.) And, while we’re at it, since the –do of hairdo is pretty transparently a combining form of do1, why shouldn’t hairdo’s be OK?

Never mind: On to the Gang of Three. First stop: Prentice-Hall’s Words into Type, which is at best equivocal.

Letters, figures, characters, signs. The plural of a letter, figure, character, or sign is expressed by adding to it an apostrophe and s.

Exceptions: In stock and bond quotations, Govt. 4s, Bergen 8s, Treas. 3¾s.

In expressions like “twos and threes,” “pros and cons,” “ins and outs,” “yeas and nays,” a regularly formed plural is used.
That is, the plural of a word referred to as a word, without regard to its meaning, is indicated by apostrophe and s.
I used too many and’s.

Not sure we want to go there (possibly in violation of one of the Don’ts for Library Users). Finally, while Words into Type does have a separate section treating the formation of words ending in o, it serves, if anything, to further muddy the water by implying that “does” might be the expected plural form of “do” (or “do’s” expected plural): “No rule without exceptions can be given for the formation of the plural of nouns ending in o preceded by a consonant. The more familiar words add es to the singular, generally speaking, while words rather recently borrowed from other languages usually add s only.” It is presumably this rule of thumb that makes “noes” the plural of “no.”

United States Government Printing Office’s Style Manual confronts the issue straight on:
“The plural of spelled-out numbers, of words referred to as words, and of words already containing an apostrophe is formed by adding s or es; but ’s is added to indicate the plural of words used as words if the omission of the apostrophe would cause difficulty in reading:
Well, are “do’s and don’ts” words referring to words, or, as Words into Type seems to imply, something else (say, actions)? The Chicago Manual of Style finesses the issue:

Noun coinages. Words and hyphenated phrases that are not nouns but are used as nouns form the plural by adding s or es. To avoid an awkward appearance, an adjustment in spelling (or sometimes an apostrophe) may be needed.


So, as far as the do’s vs. the dos are concerned, it looks as though the maybe’s have it.