Districts in eastern Germany usually have more letters , for two reasons : There are a number of exceptions e.g. Germany 's second largest city Hamburg ( HH , Hansestadt Hamburg , because of its historical membership in the Hanseatic League , reflected already in its prefix used between 1906 and 1945 ) .
Districts in eastern Germany usually have more letters , for two reasons : This is only a rule of thumb , there are a number of exceptions e.g. Germany 's second largest city Hamburg ( HH , Hansestadt Hamburg , because of its historical membership in the Hanseatic League ) or the west German district Ammerland ( WST , Westerstede is the capital of the district ) .