Definitions for "ENUM"
Electronic Number Mapping (ENUM) is an IETF Standard ( RFC 3761, was RFC 2916). It defines a DNS-based architecture and protocol by which an E.164 number can be expressed as a Fully Qualified Domain Name (FQDN). The result of an ENUM query is a series of DNS NAPTR records which can be used to contact a resource (e.g. URI) associated with a telephone number.
Electronic Number- is the convergence of PSTN and IP networks;
Telephone Electronic Number Mapping is a system where anyone that has a PSTN phone or a DID can register their phone number on an international database of VoIP users. Whenever someone with a VoIP telephone service (from a participating VSP) calls a phone number using their VoIP service, their participating VSP first checks the ENUM database. Information about ENUM is available on this site on the e164.org page.
a better choice for related constants
a choice of values (in this case, it can be either Y if the book has been sold, or N if still in possession)
a distinct type with named constant members
a code module derived from the class construct and like a class it can contian its own methods and variables
a kind of class and an annotation is a kind of interface
a low-level class that can function as a role or property
an object that defines a list of acceptable values from which the caller can choose
a string object with a value chosen from a list of allowed values that are
a way to define a number of unchangeable values, which are quite similar to consts