This chapter is limited to a discussion of the subjects of restriction and double patenting under Title 35 of the United States Code and Title 37 of the Code of Federal Regulations as it relates to national applications filed under 35 U.S.C. 111(a). The discussion of unity of invention under the Patent Cooperation Treaty Articles and Rules as it is applied as an International Searching Authority, International Preliminary Examining Authority, and in applications entering the National Stage under 35 U.S.C. 371 as a Designated or Elected Office in the U.S. Patent and Trademark Office is covered in MPEP Chapter 1800.
See MPEP § 823 for a summary of the guidance set forth in this chapter with regard to other substantive and procedural matters that generally apply to national stage applications submitted under 35 U.S.C. 371.
The general principles set forth in this chapter apply to design applications, except as identified in MPEP § 1504.05 and § 1504.06. The general principles set forth in this chapter apply to reissue applications, however see MPEP § 803.05 and § 1450 for a discussion of the prerequisites to making a restriction requirement in reissue applications. With regard to reexamination proceedings, restriction is not permitted. Basic principles of double patenting apply to reexamination proceedings, as explained in this chapter and in MPEP Chapters 2200 and 2600 (see especially MPEP § 2258).