Hello I have more beginners questions. If I

You can use whatever you like.However in the interests of realism these are the usual types of callsigns used in real-world and in FS (by most people)---------->Civil Airline flights usually use a " Flight Number" callsign - consists of an 3 letter Airline designator + the actual flight numberEG: BAW1277( British Airways 1277). DAL 9910( Delta 9910)Civil General Aviation flights ( some exec jets and most light aircraft ) use the aircraft registration= Nationality leter(s) + aircraft ident( figs or letters) EG: G-CZZZ( British) N123XX( USA)RA12345( Russian Fed)For a full list of Nationality letters past and present visit my website athttp://daveg4otu.tripod.com/pref.htmlMilitary Aircraft follow different rules-- some use 5 letter call signs similar to civil registrations EG;F-MCCV( French Army)Some use flight numbers similar to airline flights -EG RR1234( RAF Transport Command),GAF 123 ( German A F)Some use tactical callsigns usually a word + 2 figures, the USAF for instance use"REACH" + 2 figs ( REACH 05)= for MAC flights-usually C5A/C17)USNavy often use a VV prefix +letter+figures EG:VV JM123Hope this helpsDave