Since the first electronic filing in 2000, WIPO, in close co-operation with the Trilateral Offices (EPO, JPO and USPTO), added Annex F to the Patent Cooperation Treaty (PCT) with effect from 7 January 2002, to establish the technical standard (XML) necessary to implement the electronic filing and processing of international applications under the PCT. Using XML as technical standard will allow applicants to draft their application once and file anywhere in the world!

For more information click on:
http://www.wipo.int/pct/en/texts/pdf/ai_01_part7.pdf
http://www.wipo.int/pct/efiling_standard/en/index.html
http://www.wipo.int/pct/en/texts/index.htm
http://www.epoline.org/onlinefilingdocs/importingXML.doc