Valid Domain Name

Http://www.hscripts.com/tutorials/web/domain-characters.php

Domain Name:
A domain name can have alphabets, numbers and hyphen (-).

The following are the main criteria or characteristics that a domain name can have.

A) alphabets are accepted (e. g: withfriendship ).
B) numbers are accepted (e. g: 12343121 ).
C) combination of alphabets and numbers (alphanumeric) are accepted (e. g: 1d2f2g ).
D) Only non alphanumeric character that is accepted is hyphen (-) (E. g: asdd-asdd ). the name can neither start nor end with the character "-", although the character "-" is allowed inside the name.
E) Maximum length of domain name canNot be more than 64 characters long(Including extensions like. com ).
F) A valid domain extension (e. g:. com,. net,. org)

The name that does not follow the above criteria will not be accepted
Registration.

Also domain names are case in-sensitive.
They can not be differentiated based on lower or upper case letters.
I. e hioxindia.com = hioxindia.com, both are same.