It is possible to register the letters a to z, the numbers 0 to 9 and the hyphen “-“. In addition, the following characters are allowed: à, á, â, ã, ä, å, æ, ç, è, é, ê, ë, ì, í, î, ï, ñ, ò, ó, ô, õ, ö, œ, ù, ú, û, ü, ý, ÿ, ß
However, it is not possible to register domains that begin or end with a hyphen “-“ or have it in the third and fourth position, except for ASCII-encoded versions.