Flying attacks cause normal damage (1x) instead of 1/2x to all rock-typed pokemons. Description "it's not very effective" do not appear as such as "sound of damage" is same as for neutral damage.

 

Tested it on Yanmega with Air Slash against gravelers, onixes and rhyhorns.

I don't know the specifics of your tests but Yanmega can have the ability Tinted Lens which doubles the damage of resisted hits. That at least would make it appear like the resistance didn't apply.

 

In my experience in PvP this doesn't seem to be the case, but i could have missed something since i wasn't looking for it specificially. Try with some flying attacks and make sure you are aware of all abilities of the users and opponents in play and move specifics etc.

You seems to be right, Tinted Lens pokemon do not display "not very effective" while opponent has 2x resistance, but it does while he has 4x resistance (f.e. golbat attacked with bug move). It just felt weird for me.

 

My bad, topic can be closed.