Limit scope of #define labels

Question

What is the correct strategy to limit the scope of #define labels and avoid unwarranted token collision?

In the following configuration:

Answer 1

1. I think the correct strategy would be to place #define labels - in only the implementation, ie. c, files

2. Further all #define could be put separately in yet another file- say: Utility_2_Def.h
   (Quite like Microsoft's WinError.h:Error code definitions for the Win32 api functions)

   Overheads:

   1. an extra file
   2. an extra #include statement

   Gains:

   1. Abstraction: ZERO is: 0, '0' or "Zero" as to where you use it
   2. One standard place to change all static parameters of the whole module

Utility_2.h

BOOL Utility_2();

Utility_2_Def.h

# define ZERO '0'
# define ONE  '1'

Utility_2.c

# include "Utility_2.h"
# include "Utility_2_Def.h"

BOOL Utility_2()
{
    ...
}