The modern Danish alphabet is similar to the English one, with three additional letters: "æ", "ø", and "å", which come at the end of the alphabet, in that order. The letters c, q, w, x and z are only used in loan words. A spelling reform in 1948 introduced the letter "å", already in use in Norwegian and Swedish, into the Danish alphabet to replace the digraph "aa". The old usage continues to occur in some personal and geographical names; for example, the name of the city of "Aalborg" is spelled with Aa following a decision by the City Council in the 1970s and "Aarhus" decided to go back to Aa in 2011. When representing the "å" sound, "aa" is treated like "å" in alphabetical sorting, though it appears to be two letters. When the letters are not available due to technical limitations, they are often replaced by "ae" (Æ, æ), "oe" or "o" (Ø, ø), and "aa" (Å, å), respectively.