I want to register a Domain name. What are the valid characters for a domain name, and how long can it be?

The only valid characters for a domain name are letters, numbers and a hyphen “-“. Other special characters like the underscore “_” or an exclamation mark “!” are NOT permitted. Example: your name.com (not correct, no spaces allowed) Example: your-name.com (is correct) A domain name can be up to 72 characters long — including the 4 characters used to identify the Top Level Domain (.NET, .COM, .ORG, or .EDU). Do not type the www. before your domain name when registering.