A question for Rule8.3

[nyoshi]

I have a question for an exception of Rule8.3.

I think that the structure "tab" of the following sample does not have compatibility.
Is this right?

Code:

[test1.c]
struct tab {
   signed char a;
   signed short  b;
};

struct  tab a;

[test2.c]

Code:

struct tab {
   signed char a;
   signed short int  b;
};

extern struct tab a;　/* non-compliant - incompatible version */

Best Regards,
nyoshi