aaaah so it is :D
I thought that was a half life sign at the letters
(
prodigy69 broke b3ta and made everyone leave,
Thu 23 Jul 2009, 12:48,
archived)
it's a greek letter, lower-case lambda,
and is the symbol used in maths for the decay constant of exponential decay.
Which is related to the half life.
FACTS
(
Moon Girl Technologies horrendous beanbag,
Thu 23 Jul 2009, 12:53,
archived)