The C standard says nothing at all about nul or NUL. '\0' is called the null character. [Basically, the C standard is written in English and uses English words to describe things.]
A2.5.2 of my copy of K&R 2nd ed mentions the character NUL. The rest of the book, I guess, has to be EBCDIC-tolerant and just talks of the null character. Our man pages tend (and I used to encourage) using NUL-terminated as a short form of null-character-terminated, which is probably the most pedantic and correct way to say things. And actually, in the original diff, I think some of the sentences in question weren't even describing NUL-terminated strings, but pointing out that the function in question would ensure the presence of a terminating NUL...
I doubt changing things is worth the bother, but using
Amen. Paul Janzen.
