I think you can use whatever you want. The point is just to drop a quick marker that you can find later, and not interrupt your flow.
Ah, never mind. A slight refinement needed here.
AP style only spells out one through nine. 10 and above are written as numerals. So, you'd get 10 tags, not 100.
I think the regex would be: /(?<!\d)\d{1}(?!\d)/
> writing according to guidelines that insist you spell out all numbers
What? There exists such a guideline, which is not limited to very small numbers that can be written in at most two words?
That would have you writing things like one million, four hundred fifty-three thousand, one hundred fifty-eight instead of 1,453,158.
"TK: for the thousand one hundred and eleventh time, ditch this idiotic editing job"