The keywords taken into account are: break, case, char, continue, default, do, else, for, if, int, return, sizeof, switch, void and while. The followings are discarded: auto, const, double, enum, extern, float, goto, long, register, short, signed, static, struct, typedef, union, unsigned and volatile.
Obviously "." and "->" operators are also discarded, but every others are taken into account.