Yeah, the no talking is a bogus rule to me. I have always said "Mark" when the bird is in almost in the air, then dog knows to watch for a mark. Not allowed.
I think it's crud - it's meant to prevent undue steadying. In Senior, you are allowed to steady the dog though. Some judges consider any movement a break, and most of those I know won't allow steadying.
You are allowed to pull them off birds. Example: Master test. First bird is thrown in a river ont eh right. Bird 2 is far right, go bird is a flyer up the middle. To pass, you pretty much had to pull your dog off the flyer and cue them to the river bird, or it floated away.
Once the dog is released, communicating is a handle. Dogs must be handled to the bird, or it's a no pass.
Other things:
Handlier guns
all ducks/pheasants - no pigeons
Master tests are usually 2 days, junior on Sunday, senior on Saturday
No Ecollars allowed even on grounds - including bark collars
No booze allowed on test grounds during test
Ummm... I'll have to keep thinking, I think there's a few more.