Definition of "declare" for Rule 21.2

[satoshi]

Rule's title say "shall not be declared."

C90/C99 use the "declare" for function declarations and variable declarations.
And, macros are used the "define".

p.167
#define __BUILTIN_sqrt(x) (x) /* Non-compliant */

"example" is a rule violation for the macro definition.
To error the macro definitions could not be a role of rule 21.1?


-----
Best regards,
Satoshi Kawajiri