Flight number with no operator prefix? Dear God, what standards have Nav Canada sunk to? Its not uncomon in North American airspace to have more than one flight with the same flight numbers, thats why SOPs are firm on using the operator prefix, time for some re -training methinks.Maybe if Nav Canada cut out the endless drivel such as " taxi on the ramp is at your own discression" folks might pay more attention to what ATC are saying, fourteen transmissions from ground in CYOW last week just to get to the runway, we were the ONLY aircraft moving! This stuff along with some "Chuck Yeager wanabees" who seem to think that VHF is just another phone system to chatter on are becoming a major problem in North America, they need to spend some time at LHR to see and hear how to do it. {with the exception of snow removal that is!}