I think in the US "Squawk mode Charlie Charlie on the xpndr" is valid but why one controller insists on telling me that all the time is a mystery as I always put on the xpndr in mode C and they don't have ground radar,..
what really hate is when after touchdown and you are occupied the same twr controller gives fast turnoff instructions,...causes many students [solo] to stop on the runway only to be berated loudly,...
in fact there's a youtube of this behavior
I don't know the guy in the Mooney,...but I know the Mooney involved
airport involved FRG