Patents, trademarks, and copyrights. Part1:Rules of practice in patent cases. Section1.33:Correspondence respecting patent applications, patent reexamination proceedings, and other proceedings.
(a) Correspondence address and daytime telephone number. When filing an application, a correspondence address must be set forth in either an application data sheet (§ 1.76), or elsewhere, in a clearly identifiable manner, in any paper submitted with an application filing.