2.4.x/modules/core/test/conf/test13.conf

# case insensitive
<Macro FOO>
  Warning "macro FOO line 1"
</MACRO>

<MACRO bla>
  Warning "macro bla line 1"
</macro>

use foo

<macro foo>
  Warning "redefined macro foo line 1"
</macro>

use FOO

Error "done line 18."