URN structure urn:service:sname.subsname… urn:service:sname reaches any service of type ‘sname’ Examples: urn:service:sos urn:service:sos.fire urn:service:sos.police urn:service:sos.marine urn:service:sos.mountain urn:service:sos.rescue urn:service:sos.poison urn:service:sos.suicide urn:service:sos.mental-health |