domains - the basics

 

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.