The general principles relating to distinctness or independence may be summarized as follows:
- (A) Where inventions are independent (i.e., no disclosed relation therebetween), restriction to one thereof is ordinarily proper, MPEP § 806.06.
- (B) Where inventions are related as disclosed but are distinct as claimed, restriction may be proper.
- (C) Where inventions are related as disclosed but are not distinct as claimed, restriction is never proper.
- (D) A reasonable number of species may be claimed when there is an allowable claim generic thereto. 37 CFR 1.141, MPEP § 806.04.
Where restriction is required by the Office double patenting cannot be held, and thus, it is imperative the requirement should never be made where related inventions as claimed are not distinct. For (B) and (C) see MPEP § 806.05 – § 806.05(j) and § 809.03. See MPEP § 802.01 for criteria for patentably distinct inventions.