http://www.rfc-editor.org/rfc/rfc5139.txt
RFC 5139: Revised Civic Location Format for Presence Information Data Format Location Object (PIDF-LO), M. Thomson, J. Winterbottom2008-02-01T23:00:00-00:00This document defines an XML format for the representation of civic location. This format is designed for use with Presence Information Data Format Location Object (PIDF-LO) documents and replaces the civic location format in RFC 4119. The format is based on the civic address definition in PIDF-LO, but adds several new elements based on the civic types defined for Dynamic Host Configuration Protocol (DHCP), and adds a hierarchy to address complex road identity schemes. The format also includes support for the xml:lang language tag and restricts the types of elements where appropriate. [STANDARDS-TRACK]