The title of this article is very broad - and deliberately so - this way we can cover the two key areas of Domain Restrictions.
Who can register certain domain names - or specifically their extension.
The characters and number of characters (minimum and maximum characters) that can be used.
In a number of our other domain name related articles, we have superscripted some domain extensions as "Restricted".
For example the Country Code Top level Domain (ccTLD): .ad andorrarestricted
There are many, many others.
Not all country code domains are restricted - some can be registered by anyone without any restrictions at all.
So what does Restricted mean ?
Every Domain name extension will have a Regulatory Body - they set the rules as to who can register domains within their area of control.
Some Top Level Country Code Domain extensions, Second Level Country Code Domain (ccSLD) extensions, and Geographic Top Level Domains (geoTLD) have restrictions on who can register a domain for their country - the registrant may need to be either a:
- Organisation with a presence in the country.
- Have a Registered Trademark in the country.
- .eu (European Union)
- .au (Australia)
- .ad (Andorra)
The above requirements can be classed as "Local Presence Required".
Some domain name extensions are trademark names and can only be registered by the trademark owner - these are often referred to as 'Branded Domains'.
Trademarked (Branded) domain extensions include, but are not limited to
- .bbc (British Broadcasting Corporation)
Other domain name extensions are Professional Use Domains and require a Professional qualification and / or Professional Body Membership
- .law.pro (Law Professionals)
- .med.pro (Medical Professionals)
- .nur.pro (Nursing professionals)
- .vet.pro (Veterinary Professionals)
Domain name length (number of characters) - many have a requirement of:
- Minimum: 3 (Excluding the extension) there are some exceptions to this minimum.
- maximum 63 characters per label (parts of a domain name separated by a dot), with an overall maximum of 253.
Domain name characters: many require the use of letters (a - z) numbers (0 - 9) with the use of a hyphen (-) or a combination of letters numbers and hyphen(s)
Exceptions to the above are Internationalised Domain Names (IDN) extensions which typically utilise local languages such as
- Chinese characters
- Japanese characters
- Hindi characters
- Korean characters
- Russian characters
- Thai characters