What do the letters æ, ø and å mean?

The answer

They are the last three letters of the Danish alphabet, which has 29 letters, and they sort after z. Æ, ø and å are separate letters, not accented versions of a, o and a. They appear in many place names, such as Ærø and Rømø, where ø also means island, while å means stream. The older spelling aa is still used in some names, such as Aalborg, so you may see both. In digital searches, ae, oe and aa often work as substitutes, but results can differ.