Every domain in the forest needs to have a unique name. There are mainly two types of names: NetBIOS names are used for Windows (SMB)-based sharing and messaging, whereas DNS names can be resolved by the internet and different systems. When you're promoting the domain, it asks for the DNS name, as well as the NetBIOS name.
When considering the naming, keep the following points in mind:
- Don't use names that you do not legally own; if it's a fully qualified domain name, make sure that you have authority over it with the internet registrar.
- Don't use numbers and special characters that can easily confuse users.
- Don't use names associated with products and operating systems, for example, NT and Windows.
- Avoid using longer domain names or suffixes.
- Be careful with the spelling. I have seen people who deployed the entire domain structure and then realized they made a mistake with the spelling.
Once the domain name has been assigned, it can't be changed without redeployment, completing a domain rename process, or by performing domain migration. When planning names for the domain tree, try to define a standard. For example, it can be based on a continent, country, product, or service name. You can use the forest root domain name as a prefix, but it isn't a must.