#standards

This specification enumerates and describes Internet mail addresses (mailbox name @ host reference) to be used when contacting personnel at an organization. Mailbox names are provided for both operations and business functions. Additional mailbox names and aliases are not prohibited, but organizations which support email exchanges with the Internet are encouraged to support AT LEAST each mailbox name for which the associated function exists within the organization.

E.164 defines a general format for international telephone numbers. Plan-conforming telephone numbers are limited to only digits and to a maximum of fifteen digits. The specification divides the digit string into a country code of one to three digits, and the subscriber telephone number of a maximum of twelve digits.