Clarification of rule 2.5

[anuj1085]

The unused macro in "header" files are also a violation of this rule. explanation below:

File.h:
================
#define abc 10
================

Case1:
File1.c include file.h but does not use abc
Is this a violation.

Case2:
File1.c include file.h but does not use abc
File2.c includes file.h and uses abc
Is this a violation with respect to file1.c as it includes the header file but does not uses the macro.