originally did not use the letters 'F', 'I', 'O', 'Q', 'U' and 'Y' for technical reasons. But as almost all existing combinations are now used, these letters were allowed for new locations starting 2005. The letter combinations "SS" [[Schutzstaffel]], "SD" [[Sicherheitsdienst]], and "SA" [[Sturmabteilung]] are not used, due to links with the Nazi occupation in World War II.

Postal codes in Canada do not include the