it is "sitting a problem"..it is when some poser (99% of the time it is a teen age dude) wallows in his chalkbag, sprays about how rad these pieces of plastic he arranged are, and then determines your worth by whether you can"sit" on your ass and fight gravity. if you can "sit" and start his problem, than you MAY be allowed to "set" a problem.
otherwise, stick to the birthday slab and the colored alphabet holds.
I've got some rad plastic arrangements for your ass to sit start tonight punk. Also some big yellow glob called a brain came in the mail yesterday. I think I'll keep it.
Yo Ray jack dynomite! Listen to my beat box! Bew ch ch pff BEW ch ch pfff! Sweet!
A side note: You do not "set" routes outside. Nature has already taken care of that for you. One of my little pet peeves is when someone refers to another person who has bolted a route that they have "set a new route."