What other restrictions do I need to know about when registering a .au domain name?

Domain names must:
a) be at least 2 characters long;
b) contain only letters (a-z), numbers (0-9) and hyphens (-), or a combination of these;
c) start and end with a number or a letter, not a hyphen; and
d) not contain hyphens in the third AND fourth position (eg. ab — cd.com.au).

3rd Level domain names can be registered but 2nd level domains ending with .au CANNOT be registered. example.au or myname.au CANNOT be registered but example.com.au and example.net.au can be registered. There are only a small number of .au 2nd level domain names to choose from.

Each specific domain name can only be registered once. If someone else has registered your desired domain name, you cannot register it.