Conventional Gear
A/G may or may not respond 'roger' which means nothing more to me than the A/G Operator heard and understood my transmission
I'm not being pedantic (well I guess I am, but only because it is important information) but 'roger' does not mean understood, only heard.
Anyway, not trying to start an argument
Ghengis
I've heard A/G operators use the 'D' word, too, but they shouldn't, as it is a type of clearance to be given by AFISO's.