The Strasbourg Agreement Concerning the International Patent Classification (or IPC), also known as the IPC Agreement, is an international treaty that established a common classification for patents for invention, inventors' certificates, utility models and utility certificates, known as the "International Patent Classification" (IPC).
[6] The treaty was signed in Strasbourg, France, on 24 March 1971; it entered into force on 7 October 1975[1] and was amended on 28 September 1979.
The Agreement and the certified statement were registered by the World Intellectual Property Organization on 28 February 1980.
[8] As of April 2023, there were 65 contracting parties to the Strasbourg Agreement.
[3] The Holy See, the Iran and Liechtenstein signed the Agreement in 1971[9] but have not ratified it.