variable urn A string-to-URN converter. Returns null if the string is not a URN. Examples Example 1 const aUrn = urn`urn:ietf:rfc:2648`; aUrn instanceOf URN; // true aUrn instanceOf IRI; // true aUrn.namespace === 'ietf'; // true aUrn.namespaceSpecific === 'rfc:2648'; // true SeeThe IRI JavaScript module