To do a Diff is to power level a character on an MMORPG from the bottom to the top level available in record amount of playing time. MOST who do this, have intentions of their account going to a Ni Hao website (Ni Hao = gold farmer)
(Lumathus):Man where did all our tanks go? they all went to healing spec! argh!
(Unregistered): hmm maybe I should do a diff with my druid so we have a tank in guild eh.