The DP out of LGA reads:

"DEPARTURE PROCEDU Rwy 4, climb to 600 before proceeding westbound.
Rwy 13, climb to 800 before proceeding westbound. Rwy 22, climb to 1400
before proceeding westbound. Rwy 31, climb to 1200 before proceeding
southbound."

It seems kind of vague to me. Is it implied that you're supposed to
climb on runway heading? Also, what does "westbound" mean? Any heading
between 180 and 360 clockwise? But if that's the case, runway heading
is already "westbound". It all seems a little nebulous for IFR stuff.