2.4.x/modules/core/test/conf/test36.conf

<Macro warnings $u $n $u1 $n1 $u2 $n2>
  Warning "many warnings! $u $u1 $u2"
  # $n $n1 $n2
</Macro>

# warn about unused arguments
Use warnings 1 2 3 4 5 6

# may warn about empty arguments?
Use warnings '' '' '' '' '' ''

Error "done!"