While in Toronto last week I couldn’t help but admire, from the standpoint of graphic design and engaged municipal government, the timely yellow-and-white notice about handwashing that was posted in all restrooms.
But those who attend my seminars will be aware that the one subject that has had me in a cold sweat more than any other is the ambiguity associated with and and or. The result is that I’m rather paranoid about it.
The handwashing notice says, among other things, exactly when you should wash your hands. While dutifully washing my own hands, I couldn’t help but observe that the notice says that you should wash your hands before and after you “Prepare or eat food.” So, I said to myself, does that mean I would still be complying with the recommendations if I were to say to myself, “OK, I’ll wash my hands when I eat food, but not when I prepare it”? That obviously isn’t the intended meaning, but if you’re sensitized to the ambiguous or, you can spot it in all sorts of places.
And changing the or to and would simply allow the reader to say, “OK, so I don’t need to wash my hands when I just prepare food, or just eat it, as opposed to when I engage in both activities with respect to any given food.”
Toronto Public Health could have put or paranoiacs out of their misery by having “Prepare food” and “Eat food” as separate bullet points. But as MSCD 10.69 points out, it’s unreasonable to expect to be able to eliminate all ambiguity associated with and or or. Any writer is entitled to assume a rational reader, and no reasonable person would understand the handwashing notice as conveying the alternative meaning that I spotted.
But the stakes are higher in the case of contract language, which, because it regulates conduct, is limited and stylized and is subject to greater scrutiny. When drafting a contract I’d go the extra mile to avoid an ambiguous or.