Offside rule
Christ alone knows.
I imagine it's something to do with football but, frankly, the details elude me.
I shall procure a schoolgirl and question her on the matter.
ADDENDUM
(Diligent research reveals that Offside is an 'infraction in which an offensive player does not have at least two defensive players between himself and the goal line when the ball is played forward by a member of the attacking team'.
There! Now you know.
My case comes up next week.