What is the basis for including negative limitations in patent claims?

The basis for including negative limitations in patent claims must be found in the original disclosure of the patent application. According to MPEP 2173.05(i):

“Any negative limitation or exclusionary proviso must have basis in the original disclosure. If alternative elements are positively recited in the specification, they may be explicitly excluded in the claims.”

This means that negative limitations can be used to exclude alternatives that were originally disclosed in the specification. However, the mere absence of a positive recitation is not sufficient basis for an exclusion. The disclosure must reasonably convey to those skilled in the art that the inventor had possession of the claimed subject matter, including any negative limitations, as of the filing date.

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Topics: MPEP 2100 - Patentability, MPEP 2173.05(I) - Negative Limitations, Patent Law, Patent Procedure
Tags: claim drafting, MPEP, Negative Limitations, Original Disclosure, patent claims, patent law