Is double inclusion of an element in a Markush group a basis for rejection?

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.

Double inclusion of an element in a Markush group is not, in itself, a sufficient basis for rejection of a claim. The MPEP 2173.05(h) states:

“The double inclusion of an element by members of a Markush group is not, in itself, sufficient basis for objection to or rejection of claims. Rather, the facts in each case must be evaluated to determine whether or not the multiple inclusion of one or more elements in a claim renders that claim indefinite.”

The MPEP provides an example:

“For example, the Markush group, ‘selected from the group consisting of amino, halogen, nitro, chloro and alkyl’ should be acceptable even though ‘halogen’ is generic to ‘chloro.’”

Therefore, while double inclusion should be carefully considered, it doesn’t automatically render a claim indefinite or invalid.