yep, if you're describing what i think you are. it's called detuning. in general terms a board "should" have the portion of rail edge from the contact point back two inches towards the center dulled. this makes it easier to release the board as you're coming out of your turn and makes harder to catch an edge- say when your spinning, buttering, etc. it's mostly for cambered boards but i've seen folks do it on rocker boards also. there is no hard and fast rule since it mostly depends on your riding style. some ppl who spend most of their time riding park/street features will detune the entire effective edge.
Try this trick and spin it, yeah
Your head will collapse