37 CFR 1.141 Different inventions in one national application.
- (b) Where claims to all three categories, product, process of making, and process of use, are included in a national application, a three way requirement for restriction can only be made where the process of making is distinct from the product. If the process of making and the product are not distinct, the process of using may be joined with the claims directed to the product and the process of making the product even though a showing of distinctness between the product and process of using the product can be made.
Where an application contains claims to a product, claims to a process specially adapted for (i.e., not patentably distinct from, as defined in MPEP § 806.05(f)) making the product, and claims to a process of using the product, applicant may be required to elect either (A) the product and process of making it; or (B) the process of using. If the examiner cannot make a showing of distinctness between the process of using and the product (MPEP § 806.05(h)), restriction cannot be required.
See MPEP § 821.04(b) for rejoinder practice pertaining to product and process inventions.