What are Markush claims of diminishing scope?

Markush claims of diminishing scope refer to a series of claims where each subsequent claim narrows the scope of the Markush group from the previous claim. The MPEP 2173.05(h) addresses this practice:

“The use of Markush claims of diminishing scope should not, in itself, be considered a sufficient basis for objection to or rejection of claims. However, if such a practice renders the claims indefinite or if it results in undue multiplicity, an appropriate rejection should be made.”

This means that while using Markush claims of diminishing scope is not inherently problematic, it could lead to issues if it creates indefiniteness or results in an excessive number of claims. Examiners and practitioners should evaluate such claim sets carefully to ensure they meet all requirements for clarity and conciseness.

To learn more:

• Markush claims
• diminishing scope
• patent claim strategy
• claim construction