===SORRY!===
Cannot call ACCEPTS(Regex: Mu); none of these signatures match:
    (Regex:D $: Mu:U \a, *%_)
    (Regex:U $: \topic, *%_)
    (Regex:D \SELF: \topic, *%_)
    (Regex:D \SELF: @a, *%_)
    (Regex:D \SELF: %h, *%_)