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

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

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.

To learn more:

• alternative elements
• negative limitations
• patent claims
• specification