http://www.perlmonks.org?node_id=985808


in reply to A question of style: Composite keys to multiple values

$Fields{lc("$ExtA|$ExtB")} = { A => $IntA, B => $IntB };

You might also want a subroutine as interface to your %Fields hash so you aren't writing lc("$ExtA|$ExtB") in more than once place.

- tye