Addresses used in examples should use fully qualified domain names instead of literal IP addresses, and should use example FQDNs such as "foo.example.com" instead of real-world FQDNs. See RFC 2606 for example domain names that can be used. Note that the entire “.example” TLD is reserved, allowing for arbitrary subdomains (in particular, ones that are not considered same-origin on the web.
Literal IP addresses used in examples should be from the example ranges set aside for this purpose. For IPv4, these are defined in RFC 6890; for IPv6, see RFC 3849. IPv6 examples should be used to conform with the IAB Statement on IPv6.
Telephone numbers used in examples should be those numbers that were reserved for examples or fictitious use. Available numbers for use in examples are:
USA: +1-<area code>-555-<0100-0199>
For USA examples, also see ATIS-0300115.