Can alternative elements positively recited in the specification support a negative limitation?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

Yes, alternative elements positively recited in the specification can support a negative limitation in patent claims. This is explicitly mentioned in MPEP 2173.05(i):

“If alternative elements are positively recited in the specification, they may be explicitly excluded in the claims.”

This means that if the original disclosure describes multiple options or alternatives for a particular feature or component, you can later exclude one or more of these alternatives in the claims using a negative limitation. For example:

• If the specification describes a device that can use “metal, plastic, or ceramic” for a component, you could later claim “wherein the component is not made of metal.”
• If a process is described with optional steps A, B, and C, you could claim “a process consisting of steps A and C, wherein step B is not performed.”

However, it’s important to ensure that the negative limitation doesn’t introduce new matter and is supported by the original disclosure.