Dave it's a simple matter of typing in the callsign and then the matching flight comes up. However it only works with exact matches, so if you call up as Jabiru 1234, we would try searching as 1234 but if you put JAB1234 as your flight is in NAIPS we wouldn't get a match. If AIP/NAIPS made it clear that R1234 was the ID to use i'm sure the controllers would then know that's what to search for. So far I've come across JAB1234, UL1234, 241234 and 1234 as examples that were used. A standard would be welcomed