High Quality Content by WIKIPEDIA articles! High Quality Content by WIKIPEDIA articles! The Patent Law Treaty (PLT) is a patent law multilateral treaty concluded on 1 June 2000 in Geneva, Switzerland, by 53 States and the European Patent Organisation (an intergovernmental organization). Its aim is to harmonize formal procedures such as the requirements to obtain a filing date for a patent application, the form and content of a patent application, and representation. As of October 28, 2009, the PLT has 22 Contracting states, while 59 States and the European Patent Organisation have signed the treaty. The PLT will enter into force for Liechtenstein, the 21st Contracting State, on 18 December 2009, and for France, the 22nd Contracting State, on 5 January 2010.