Numbering Authorities are organizations responsible for managing and allocating unique identifiers for various systems, such as telecommunications and the internet. They ensure that each identifier, like phone numbers or IP addresses, is unique and can be used without confusion. This helps maintain order and efficiency in communication networks. One well-known example of a Numbering Authority is the Internet Assigned Numbers Authority (IANA), which oversees the global allocation of IP addresses and domain names. Another example is the International Telecommunication Union (ITU), which manages numbering resources for global telecommunications.