What restrictions are there on the domain name I can choose to register?

Domain Names have a variety of basic rules, in general domains must:

- Use only letters, numbers, or hyphen ("-").

- Cannot begin or end with a hyphen.

- .com, .net, .org and .info domain names cannot exceed 67 characters total.

- .info and .biz must have at least 3 characters not including .info or .biz.

- Other domain names cannot exceed 22 characters, not including the extension.

- Domain names are not case sensitive.

- Domain names cannot include spaces.

- 2 letter domains are not permitted.

Strictly speaking domain shouldn't begin with a number either, however in practice it is possible in most circumstances.