Question about SF High Altitude ATC

Today I was listening to San Francisco high altitude ATC on 8843 and noticed that they are not using the regular flight numbers. Instead they are using the numbers listed below to identify the flight.



I listen to this quite often and like tracking high altitude flights on FlightAware, especially international flights.



Anyone know what these ID numbers are and how to track them in FlightAware or other App?



This is the only frequency I noticed this on, all of the others are business as usual.



N222LX

N851GG

N482JM

HL7526

N484JM

N415QS

N675BP

Question about SF High Altitude ATC