What is the "No Step" flap thingy used for on an A320 engine? There is a small plate sticking out of an A320's engine narcelle with "No Step" written on it. I tried taking a picture of it, which in retrospect didn't turn out as good as I wanted it to be, but I hope it helps:



Anyway, I'm wondering what it's used for? It's only on one side towards the aircrafts body and it seems to be too small to be an aerodynamic surface. I suspect it's used during maintenance?
It's a vortex generator explained in full in this question

"NO STEP" means don't put your foot on it. It's too weak to hold a person's weight and would get damaged.