How does adding a specific limitation to a claim affect its scope?

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.

Adding a specific limitation to a claim typically narrows its scope. According to MPEP 2163.05:

“The introduction of claim changes which involve narrowing the claims by introducing elements or limitations which are not supported by the as-filed disclosure is a violation of the written description requirement of 35 U.S.C. 112(a) or pre-AIA 35 U.S.C. 112, first paragraph.”

This means that while adding a limitation can narrow a claim’s scope, it must be supported by the original disclosure to avoid violating the written description requirement.