4.4. Transport and Display

When URNs are transported and exchanged, they MUST be represented in the format defined herein. Further, URN-aware applications are strongly encouraged to offer the option of displaying URNs in this canonical form to allow for direct transcription (for example by copy-and-paste techniques). Such applications might support the display of URNs in a more human-friendly form and might use a character set that includes characters that are not permitted in URN syntax as defined in this specification.

To minimize user confusion, any application displaying URIs SHOULD display the complete URI (including, for URNs, the "urn" scheme and any components) to ensure that there is no confusion between URN NIDs and URI scheme identifiers. For example, a URI beginning with "urn:xmpp:" [RFC4854] is very different from a URI beginning with "xmpp:" [RFC5122].