WITCH hat: Revision 3
"hat", "disjunct", "but not", "upto"
-- Used when something "wears many hats"
Operators containing this character
~^ and +^ and ?^ An exclusive or bitwise operation (or an invert, if only one argument)
When used inside regexes
Variable names starting with hats inside a pointy block or sub are placeholder variables
Method names starting with hats are metaclass methods
Old, deprecated, or other language uses
^ was bitwise exclusive or in Perl 5. In Perl 6 that's ~^, +^, or ?^ for bitwise, and ^^ in logic.