RFID Tagged Filament

How do we know if the filament we are ordering here,Amazon,EBay or anyplace for that matter is the RFID tagged? I would guess most places have old stock they would look to sell first. An open RFID tag system would be great if you could slap your own on the side of a spool and have the CFS pull the setting automatically. I realize you most likely have proprietary keys keeping the system closed. But a secondary open system would be great