That may well be one of the most annoying phrases – at least in its written form.
1. It’s got an apostrophe in the wrong place! My bete noir if ever there was one!
2. It’s not even internally consistent. If you were going to have an apostrophe in the first, you’d have to have it in the second as well – so Do’s and Don’t’s – which clearly looks ridiculous, although I have actually seen it written like this in some places.
3. It should just be Dos and Don’ts. And if you’re not happy with Dos because you hate PCs, then DOs and DON’Ts is probably the way to go.
Ok. End rant,