What is the difference between claim breadth and indefiniteness?

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.

It’s important to distinguish between claim breadth and indefiniteness in patent examination. The MPEP clarifies this distinction:

“Examiners, however, are cautioned against confusing claim breadth with claim indefiniteness. A broad claim is not indefinite merely because it encompasses a wide scope of subject matter provided the scope is clearly defined.”

Key points to understand:

• A broad claim can be definite if its scope is clearly defined
• Indefiniteness occurs when the boundaries of the protected subject matter are not clearly delineated
• A genus claim covering multiple species is not indefinite solely because of its breadth
• Indefiniteness arises when it’s unclear which species are included in a genus claim

Examiners should focus on whether the claim boundaries are clear, not on the breadth of the subject matter covered by the claim.