error[tan19]

Any IRI beginning urn: must continue with a name that is part of the official IANA Registry of URN Namespaces. See RFC 2414, https://tools.ietf.org/html/rfc8141, and https://www.iana.org/assignments/urn-namespaces/urn-namespaces.xhtml

Affects: <IRI>

Used by template ŧ core-expansion-terse