Domains come in all shapes and sizes, but there are a few restrictions on what you can have and how it’s formatted.
You can have a mixture of letters, numbers, and hyphens, but the domain can’t start or end with a hyphen or double-hyphen in the middle.
A domain name registration can’t have more than 63 characters in total. Shorter domains are usually considered more desirable, as they will be more memorable and easier to search.