Early C only used the first few characters of function names

It turns out there's a reason that the C standard library has such cryptic names for its functions:

Early C (including ANSI C, a.k.a. C89, if I understand correctly) required external functions to have their first 6 characters be unique.

I even saw a claim that strncpy would have been strcpyn if not for this limitation. As much as I enjoy the simplicity and ubiquity of C, it does come with a noticeable amount of annoying baggage.