Thanks for the help. Sentences like "TSO-C199 devices are a reduced feature Mode-S (and optionally 1090ES Out) based traffic saftey beacon system hopefully suitable for gliders, balloons and maybe UAVs inter-operating with GA and above aircraft equipped with PCAS/TCAD/TCAS/ADS-B In" are deeply helpful to those of us working our way into this topic. I'm deeply indebted.