Yes, there are actual rules for HUMP!, as well as an Extra Credit incentive. To wit:
"A jury of local sex experts, sex-positive film critics,
and sex-obsessed porn fans select HUMP! entries for
inclusion in the festival. We look for hotness and
humor-films don't have to be slick, just hot and/or
funny-and entries that are made especially for HUMP!
are likelier to make the cut. To prove that you made
your film just for HUMP!, include one or more of these
props and/or locations in your HUMP! submission:
PROPS