In force beginning on January 1, 2013, this bilateral system has been developed by the EPO and the USPTO. It combines the best classification practices of each.
Used by the EPO for carrying out patent application searches, it is built on top of the International Patent Classification system (IPC), and is updated often.
WIPO GOLD is a free public resource which provides a one-stop gateway to WIPO’s global collections of searchable IP data. It aims to facilitate universal access to IP information.
World Intellectual Property Organization (WIPO)'s searchable database of Patent Cooperation Treaty (PCT) international patent applications. Includes published bibliographic data 1978 to present and text of description and claims for applications published in English, French, German or Spanish July 1998 to present.
The Scientific and Technical Information Center (STIC) at the USPTO has a substantial collection of patents from other countries. See this document for a detailed list.
