Originally Posted by
IO540
The phrase "known ice" applies to FAA registered planes. It doesn't apply to G-reg for example; the system there is different.
Of course "known ice" applies to G-reg aircraft. The AFM is substantially the same as the FAA's POH.
The FAA's AC 23.1419-2C, AC 25.1419-1A deal with what the systems have to be capable of to get known icing certification.