24-bit hex address from the message's AA field. A real, registered ICAO
Mode-S address when messageSource is icaoDirect/icaoTisb/adsr -
an anonymous or ground-assigned identifier, not a registered ICAO
address, when messageSource is anonymousDirect/anonymousTisb.
The decoded callsign and category.
Discriminant tag identifying this as a decoded aircraft identification message.
Where this message's address and data actually came from - see MessageSource.
A DF17/18 extended squitter aircraft identification message.