An ENUM registration represents a range of telephone (E.164) numbers belonging to a single legal entity -

For example, Nominet's range of telephone numbers is
+441865332200 to +441865332499 

A telephone number is converted to a domain name in the following way:

• Start with the full E.164 number, including country and area code.
• Remove all characters except digits
• Reverse digit order
• Put dots between each digit
• Add the suffix e164.arpa.

So, +441865332200 converts to 0.0.2.2.3.3.5.6.8.1.4.4.e164.arpa
and +441865332499 to 9.9.4.3.3.5.6.8.1.4.4.e164.arpa.

Registration of an ENUM representing the above range of telephone numbers will result in 299 domain names. Each of these domain names will resolve in the e164.arpa zone file and will have the same nameservers, those assigned to the ENUM.