Singapore is A380s have a flag, but not next to the registration, however, Emirates' A380 has a (German) flag adjacent to it is registration. Is it compulsory? Why do most airlines have the flag adjacent to the registration? Is the flag on the Emirates' because the aircraft was registered in Germany? If so, why did not Singapore is have a German flag?

NOTE: l know Emirates do not have an A380 yet, it is being completed in Blagnac and Finkenwerder and I've seen pictures.

The Emirates aircraft has a German flag because the aircraft is still in airbus ownership,presumably in Germany, not having been delivered yet. No they are not compulsory as far as l know, just look at BA aircraft.

Yes, a flag has to be on the aircraft for international flights. Even going from the US to Canada and Mexico, an American flag is required.

The flag denotes country of ownership or more speciically the country where the acft is regsitered. in. It is a visual symbol for the general public who r not in the know..The flag is notmandatory at all. For instance :any acft that is US owned will start with N in the tail number or registration number. ''N'' denotes acft ownned /regsitered by a USA company...Germany is ''D'' France is ''F'' .There is not always a sensible explanation for the lettering unless u research .it..For instance the ''D'' in German acft is for Deutshland ..