The registration process of a .cat domain with special characters does not work the same as with other domain extensions. When you want to register a .cat domain with a special character, you should first have registered the homonymous domain without this character. The process to follow will be as follows:
A .cat domain can have for FREE all the variants that its name admits.
In the following table we show the valid variations with special character with respect to the homonym:
à---------------------a -> If we want to register tarlà.cat, initially we will register tarla.cat
é---------------------e -> préstec.cat => prestec.cat
è---------------------e -> nèctar.cat => nectar.cat
í----------------------i -> país.cat => pais.cat
ï----------------------i -> països.cat => paisos.cat
ó---------------------o -> organització.cat => organitzacio.cat
ò---------------------o -> anònim.cat => anonim.cat
ú---------------------u -> única.cat => unica.cat
ü---------------------u -> reüll.cat => reull.cat
ç---------------------c -> força.cat => forca.cat
l·l--------------------l-l -> goril·la.cat => gorila.cat