wikipedia.org:
https://en.wikipedia.org/wiki/Domain_Name_System

Note: The applicable Requests for Comments need a real technical specification.

Professional Domain Name System, eg:
https://dnsmadeeasy.com / https://constellix.com

Requirements for Domain Name Systems:

• Two-Factor-Authentication / several users
• Authorization by user name
• TLSA and CAA available
• Download print-out of setup
• History of changes
• Proper domain holder names

Example of Domain Name System settings, in Dutch: