In developing your domain name, there are distinct characters that you can use while others are not allowed. The control of characters for usage in domain names are specified for some reasons, one to avoid similar domain assignment and two, to facilitate separation of domain name characters from non-domain one in the process of translating the domain name into IP address.
As such, here are the characters allowed in a domain name:
1. Alphabetical Letters
Alphabetical letters represent the 26 alphabets ranging from A-Z. When developing your site domain name, you are allowed to use any letter of the alphabet. Depending on your preference, you can combine the letters in a way that will suit your purpose. For instance, you can develop domain names such as zxytu.com, badcp.org, omnq.ca and so on.
Apart from using alphabetical letters, you can use any combination of numbers between 0 and 9. If your love belongs to numbers, you are allowed to combine them and come up with your domain. For example, you can have domain names such as 100.com, 123.org, and 999.biz and so on if there is no one else who have already registered such a domain.
In addition to letters and numbers, hyphens are other characters allowed in a domain name. If you find that your preferred domain name is taken, you are allowed to use a hyphen. However, you can only use a hyphen in between two words. You cannot use it at the beginning or the end of your domain name.
Use of Hyphen has both merits and demerits. On the substance side, they can help your site to rank better in the search engines. However, it depends on the positions of the Sites with a similar domain name. For instance, a site by the name dreamwise.com ranks better, and you come up with the name dream-wise.com, there is a possibility of ranking better.
On the demerit side, hyphened domains have close associations with spam and low-quality sites. As such, using a hyphened domain name may affect the reputation of your site.
Accordingly, other characters allowed in a domain name are periods. Each site has a period mostly recognized as ‘dot.’ In particular, your domain name is incomplete without a period.
In whole, numbers, periods, hyphens and letters are the main components found in a domain name. However, other language characters such as Chinese, Arabic, and Russian are also becoming standard parts of domain names.
— VisionaryCode (@VisionryCode) 30 de mayo de 2017