Altho idiomatic that is perhaps slightly confusing because K&R 2nd ed uses the modern way of specifying parameters. I would prefer to say "pre ANSI C" or something of that kind.
You would be rewriting history if we changed that now. It has been referred to K&R style C since the ANSI standard. The second edition of the C Programming Language was ANSI. My copy of the second edition has "based on the draft-proposed ANSI C" on the cover, but later ones just have "ANSI C". I think mine is almost identical to the ANSI version.
Every copy of K&R that uses ANSI has ANSI written somewhere on the cover. I've seen the first edition, and the content is pretty similar if not identical, save for the ANSI changes. But it is all in the K&R style.
