I'm not from around here so don't know about any specific local etiquette. With that in mind: waiting until the leader below you is either at a belay or at a spot where they can tell you they're safe is common courtesy, IMO. Beware of just yelling 'rope!' without looking for feedback. I was once leading a traversing route, when a rope fell from above and whacked my ropes behind me, pulling down on me. Thankfully I was at a pretty good stance, so no biggie, but kind of scary. When the guys rapped down they swore they yelled 'rope!' but I sure didn't hear them.
Anyway, just to say: play nice, kids!