+@item
+C11 @code{_Static_assert} and C++11 @code{static_assert}
+are keywords that can be used without including @code{<assert.h>}.
+The Gnulib substitutes are macros that require including @code{<assert.h>}.
+@item
+The C11 @code{static_assert} and @code{_Static_assert} can also
+be used within a @code{struct} or @code{union} specifier, in place of
+an ordinary declaration of a member of the struct or union. The
+Gnulib substitute can be used only as an ordinary declaration.
+@item
+In C99, @code{assert} can be applied to any scalar expression.
+In C89, the argument to @code{assert} is of type @code{int}.