With respect to ATC callsigns there are more and more similar-sounding callsigns leading to potential hazardous situations where a pilot may take an ATC clearance meant for someone else as his own, such as a climb or descent clearance. ATC Service providers have asked airlines to try to use more unique callsigns to avoid this. In this case it has probably been identified that another airline flying in or out of DXB or JFK every day at approximately the same time also used the ‘5’, such as ‘Speedbird 5’ or ‘SkyDubai 5’. Adding the ‘Kilo Poppa’ just reduces the risk of any callsign confusion on the radio.