> That is, for lack of a better term, a "Microsoft-ism"; in MS documentation, "ASCII" consistently means "single-byte or MBCS" and is interpreted relative to the current codepage

I've read my share of MS docs and I do not recall ever seeing this to be the case. Like the parent says, I've seen "ANSI" used to refer to that, not ASCII. Do you have any examples of where they say "ASCII" where the intention is obviously something broader than 0-127? It makes me wonder how I've missed this if that's the case.