“DOs and DON’Ts” or “Do’s and Don’ts”?

I was minding my business on the internet when I happened upon a review of the new Microsoft Manual of Style for Technical Publications on Kai Weber’s Tech Writing Blog. It was an interesting review (you should go read it) so I thought I’d have a look at what the going price is for the new Manual of Style.  A Google search for Microsoft Manual of Style took me to the Microsoft webpage on the third edition where I saw a bit of text that had my inner-editor shouting “NO NO NO!”.

Use technical terms correctly and consistently—including do’s, don’ts, and alternatives for usage.

When I was first taught about the apostrophe, the rules were simple:

1. An apostrophe signifies a contraction
   Example: “I cannot” contracted to “I can’t”
2. An apostrophe signifies possession
   “Alice’s new shoes”

But as I got further in schooling, there seemed to be this grey-zone of plurals which seemed better with apostrophes. Wikipedia mentions some such as when pluralising lower-case letters:

Be sure to dot your i’s and cross your t’s

It’s certainly not the “grocers’ apostrophe” that raises the hackles of copyrighters everywhere (Apple’s £1.50/lb). Surely nouns shouldn’t ever require an apostrophe to be pluralised… But what about those grey-zone ones?

Is the phrase do’s and don’ts correct in its punctuation?

It seems to me that it’s the pluralisation of do that seems to visually require the apostrophe. Without it, it risks being mis-read as a mis-spelling of does, or perhaps (Microsoft) DOS.

I, personally, would use DOs and DON’Ts, relying on the difference in capitalisation to make it easily readable. But which is right? I struggle to think of any other phrase that requires the pluralisation of do, this shortened phrase that means “A list of things to do and a list of things to not do”. Using the capitalisation also invokes the image of two side-by-side lists, topped by the words DO and DON’T. But does anyone agree with me?

I did another quick Google search for Do’s vs DOs to see what what the forums of English pedants might suggest. Here’s a quick summary of  the first few  Google hits:

To be honest, a lot of the forums in the first page of hits seemed more concerned by the Don’ts, assuming that there SHOULD be an apostrophe in do’s so should it be written don’t’s. And no one seems to care about my solution of DOs.

Conclusion: These days, it seems like you can do whichever makes you happiest with this particular phrase. Oh, well. It’s a good thing I don’t use the phrase in documentation.