PublicIdentifier

 
													A public identifier (in the sense defined by the XML 1,0 Specification) for a NewsItem. This is the NewsML URN, and must be constructed as follows: 
													urn:newsml:{ProviderId}:{DateId}:{NewsItemId}:{RevisionId}{RevisionId@Update}
													where {x} means "the content of the x subelement of the NewsIdentifier" and {x@y} means "the value of the y attribute of the x subelement of the NewsIdentifier", with the exception that if the Update attribute of the RevisionId element has its default value of N, it is omitted from the URN.
													Note that the set of characters that can be directly included within a URN is limited.  The allowed characters are specified by the Internet Engineering Task Force (IETF) in its Request For Comments (RFC) number 2141.  This document is available at http://www.ietf.org/rfc/rfc2141.txt.  Any character that is not within the permitted URN character set must be converted to a sequence of legal characters as described in RFC 2141.
													Note that the existence of this URN enables the NewsItem to be referenced unambiguously by pointers from other XML elements or resources. Within such pointers, if the RevisionId, its preceding : character and its following Update qualifier are omitted, then the pointer designates the most recent revision at the time it is resolved. Version 1.1.2 Pattern corrected for Date component