strncat null termination

[unregistered]

according to
http://www.cppreference.com/wiki/c/string/strncat
it says

char *strncat( char *str1, const char *str2, size_t count );
The function strncat() concatenates at most count characters of str2 onto str1, adding a null termination.

Does count include or exclude the null termination that is added at the end?

[Galik]

Exclude.

http://www.cplusplus.com/reference/clibrary/cstring/strncat/