What is the legal concept of estoppel in patent interference proceedings?

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Source: FAQ (MPEP-Based) BlueIron Update: 2024-09-29 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. In patent interference proceedings, estoppel is a legal concept that prevents a party from raising an issue if they have already lost on that issue during the interference. This principle is outlined in MPEP 2308.03(a) , which states: “A party is barred (estopped) from raising an issue if the party lost on the issue during the interference.” This means that if a party has unsuccessfully argued a particular point during an interference proceeding, they cannot later attempt to re-litigate or raise that same issue in subsequent proceedings or patent applications. Related Rules from the Manual of Patent Examining Procedure 10 rules Collapse Party Barred from Raising Lost Issue During Interference MPEP 2308.03(a) Losing Party Cannot Take Inconsistent Action Post-Judgment MPEP 2308 Prohibited Losing Party Cannot Reopen Issues Adjudicated Against Them MPEP 2308 Prohibited Estoppel After Judgment Disposes of Issues MPEP 2308 Prohibited Examiner Must Maintain Rejection Unless Overcome MPEP 2308 Required Estoppel After Judgment for Properly Decided Issues MPEP 2308 Prohibited Adverse Judgment Requires No Further Office Action MPEP 2308 Prohibited Adverse Judgment Is Final Disposal of Claim MPEP 2308 Prohibited Examiner Must Resume Prosecution After Interference Ends MPEP 2308 Examiner Must Reopen Prosecution for Further Action Recommendations MPEP 2308 Required Other Related FAQs 5 FAQs Collapse What is the difference between losing on a compound claim versus a method claim in patent interference? What is an example of a partial loss in a patent interference proceeding? Can a party lose on one issue but not on another in a patent interference? How does losing on an issue in a patent interference affec...