Spazsinbad-
Taipan isn't actually the aircraft Callsign it's the ADF name for it.
as in the EC655 "Tiger"
Probably because as Eurocopter call the MRH90 the TTH and that isn't a name as such.
723 Sqn of RANHFV fame at Nowra still use the "Taipan" callsign as in "Taipan 19 finals rwy 26" for the Squirrels.
Clear as mud??
I'm going to use that Nepalise in day to day conversation!