What characters are allowed in a domain name? Print

Regardless of the extension, all domain names must follow the same character rules... You can use letters (abc), numbers (123) and dashes/hyphens (---). Spaces are not allowed and the domain can't begin or end with a dash.

A little known fact is that you CAN have multiple dashes right next to each other. (e.g. domain--names.com) Opened up a few more possibilities?