replacing the post-war system. The occupation zones were no longer referred to, instead the new system based on the districts of Germany. Each of these was assigned an alphabetic code which had its origin in the name of the district, i.e. of the city or of the capital of the rural district. Quite often, a “district-free” city was surrounded by, or adjacent to a rural district of the same name. In this case, they would both share the code as well as the name, yet devise a way how to split the possible alphanumerical combinations. The number of letters in the area code hints at the size of the district. The basic idea was to even out the number of characters on all licence plates, because the most populous districts would have more cars and, therefore, more digits after the prefix. The largest German cities generally only have one-letter codes (B=Berlin, M=Munich (), K=Cologne (), F=, S=, H=), while most other districts in Germany have two- or three-letter codes. Therefore, cities or districts with fewer letters are generally assumed to be bigger and more important whereas three-letter codes tend to be regarded as rural and dull. Reflecting that, most districts aimed for a combination with fewer letters for their prefix code. The most significant exception of the one-letter code is Germany's second largest city which bears HH for , because of its historical membership in the Hanseatic League, reflected already in its prefix used between 1906 and 1945. A similar principle applies to Bremen and , forming the state Free Hanseatic City of Bremen and sharing the common prefix HB (1906–1947, and again since 1956). Likewise, received its former prefix HL, already used between 1906 and 1937 when its statehood was abolished. The first drafts, however, had to be altered in a few cases. The district of Wittlich rejected the code WC, understandably, and received WIL instead. The code KZ, initially projected for Konstanz, was withdrawn fast, due to recent history, and replaced by KN. Neither were SA, SS or HJ considered to be issued. The code SD was projected for Stade and was finally altered into STD after protests from that district who did not want to bear the abbreviation of the . When originally planned, the system included codes for districts in Eastern Germany which were to be reserved until reunification. That included the territory of the GDR