Every macro should be commented to explain its goal and how it works. This comment can be located just before or after the macro definition.
Noncompliant code example
DEFINE my_macro.
...
END-OF-DEFINITION.
Compliant solution
* here is
* my comment
DEFINE my_macro.
...
END-OF-DEFINITION.
or
DEFINE my_macro.
* here is
* my comment
...
END-OF-DEFINITION.