What is the difference between one-way and two-way distinctness in patent restriction requirements?

In patent restriction requirements, the concepts of one-way and two-way distinctness are important for determining whether inventions are distinct:

• One-way distinctness: Generally sufficient for inventions in different statutory categories (e.g., a product and a process of making it).
• Two-way distinctness: Required for inventions in the same statutory category (e.g., two related products or two related processes).

MPEP 806.05 states: In applications claiming inventions in different statutory categories, only one-way distinctness is generally needed to support a restriction requirement. See MPEP § 806.05(c) (combination and subcombination) and § 806.05(j) (related products or related processes) for examples of when a two-way test is required for distinctness.

Two-way distinctness means that the inventions must be shown to be distinct from each other in both directions. For example, for related products, it must be shown that Product A could not anticipate or render obvious Product B, and vice versa.

To learn more:

• one-way distinctness
• two-way distinctness
• restriction requirement
• patent examination
• statutory categories