A domain name can be up to 63 characters plus the extension (.com, .net, .org etc.). It can contain upper and lowercase characters (A-Z,a-z), numbers (0-9), or both. It can also contain a dash “-” (example: domain-register.com).”Case” (upper or lower) does not matter with domain names. The domain name “Larry.com” is the same as “LARRY.COM” or “LarRy.Com”.