How do transitional phrases affect the interpretation of Markush groups in patent claims?

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Source: FAQ (MPEP-Based) BlueIron Update: 2024-09-30 10 Rules 5 Related FAQs 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. Transitional phrases can significantly impact the interpretation of Markush groups in patent claims: “Consisting of” with Markush groups: Limits the claim to only the listed members of the Markush group. “Comprising” or “including” with Markush groups: Generally interpreted as open-ended, allowing for additional elements beyond those listed. The MPEP 2111.03 states: “ A claim element defined by selection from a group of alternatives (a Markush grouping; see MPEP § 2117 and § 2173.05(h)) requires selection from a closed group ‘consisting of’ (rather than ‘comprising’ or ‘including’) the alternative members. “ However, the interpretation can vary based on the specific language used and the context of the invention. Examiners and practitioners should carefully consider the transitional phrase when evaluating the scope of Markush groups in claims. Related Rules from the Manual of Patent Examining Procedure 10 rules Collapse Scope Defined by Transitional Phrases MPEP 2111.03 Claim Must Consist of Alternatives MPEP 2111.03 Comprising Is Open-Ended for Additional Elements MPEP 2111.03 Permitted Consisting of Does Not Limit Entire Claim MPEP 2111.03 Claims Using Consisting Of Are Closed To Unrecited Elements MPEP 2111.03 Claim Element Must Be Selected From Closed Group MPEP 2111.03 Comprising Is Inclusive of Additional Elements MPEP 2111.03 Consisting of Limits Only Recited Elements MPEP 2111.03 Claim Can Include Combinations of Alternatives MPEP 2111.03 Permitted Markush Group Presumed Closed Without Qualifying Language MPEP 2111.03 Other Related FAQs 5 FAQs Collapse How does the transitional phrase &#8220;composed of&#8221; compare to &#8220;consisting of&#8221; in patent claims? How does the phra...