There was a hacker news discussion a while back by one of the principals of Coverity in which they asserted, with no small experience, that there is no such thing as a C language. This is due to the wide number of variations in what compilers accept and that users of C compilers expect.
Sure there is an ideal, but practically, there is not consistent definition of the C language.
The article discussed was this one in CACM (link is to discussion on Lambda the Ultimate) http://lambda-the-ultimate.org/node/3824 . I remember seeing it on HN too, but couldn't find the page immediately.