Patent Prosecution History: Why It Matters in Litigation

When we analyse patent disputes, one of the most critical—yet often overlooked—sources of evidence lies hidden in plain sight: the patent prosecution history. Patent prosecution history estoppel can fundamentally alter the landscape of infringement claims, potentially barring entire theories of liability that might otherwise succeed. Understanding how to access, analyse, and leverage this prosecution record is essential for any technical expert working in patent litigation.

Important: This article provides general information about patent prosecution history and estoppel doctrine for educational purposes. It is not legal advice and should not be relied upon as such. Patent litigation involves complex legal considerations that require qualified legal counsel. Always consult a solicitor or patent attorney before making strategic decisions based on prosecution history analysis.

The prosecution history, also known as the "file wrapper," contains the complete record of communications between the patent applicant and the examining authority throughout the patent application process.¹ This record can impose powerful limitations on claim scope through prosecution history estoppel doctrines, making careful file wrapper review indispensable to both infringement and validity analyses.²

What Is Prosecution History

File Wrapper Contents

The prosecution history encompasses every document and communication exchanged between a patent applicant and the patent office from filing through issuance or abandonment.³ This comprehensive record includes office actions from examiners, responses from applicants, claim amendments, and all formal correspondence that shapes the patent's final form.⁴ Under the regulatory framework established by Title 37 of the Code of Federal Regulations, all documents filed during prosecution become part of the official file wrapper record according to USPTO procedures detailed in the MPEP.⁵

Key components of a typical file wrapper include:⁶

• Office Actions: USPTO examiner rejections, requirements, and allowances
• Office Action Responses: Applicant replies addressing examiner concerns, governed by 37 CFR § 1.111 for timely responses⁷
• Claim Amendments: All changes to patent claims during prosecution, structured according to 37 CFR § 1.121⁸
• Information Disclosure Statements (IDS): Prior art submitted by applicants under MPEP § 609⁹
• Examiner Interview Summaries: Records of discussions between applicants and examiners
• Original Application: The initially filed patent application and supporting materials
• Request for Continued Examination (RCE): Submissions under 37 CFR § 1.114 when prosecution is closed¹⁰
• Amendments After Final Action: Permitted under 37 CFR § 1.116 with specific limitations¹¹

Patent Office Correspondence

Every formal communication becomes part of the permanent prosecution record. This includes not only written documents but also summaries of examiner interviews, which must be made part of the record under MPEP 713.¹² These interview records can be particularly significant because they often contain explanations of claim scope that may not appear elsewhere in the written record.¹³

Amendment History and Examiner Rejections

Perhaps most critically for litigation purposes, the file wrapper contains the complete history of how and why claims were amended during prosecution. Each amendment represents a potential source of prosecution history estoppel, particularly when amendments are made in response to prior art rejections or other patentability concerns.¹⁴ The Federal Circuit has emphasised that prosecution history estoppel may apply to any claim amendment made to satisfy Patent Act requirements, not just amendments made to avoid prior art.¹⁵

How to Access Prosecution History

USPTO PAIR and Patent Center

In the United States, patent prosecution history is primarily accessed through the USPTO's Patent Center platform.¹⁶ This system replaced the legacy Public PAIR system and provides comprehensive access to file wrapper documents for applications filed after 1 January 2001.¹⁷ Users can search by patent number, application number, or other identifiers, then navigate to "Documents & Transactions" to view and download prosecution history files.¹⁸

The USPTO's Open Data Portal also provides access to patent file wrapper data through structured databases and APIs, enabling bulk analysis of prosecution patterns.¹⁹ Files are available as PDFs with a maximum file size of 35 MB per download in some cases.²⁰

EPO Register

The European Patent Office maintains the European Patent Register at register.epo.org, providing free 24/7 access to prosecution history for European patent applications.²¹ The register contains procedural documentation from publication through the end of the procedure, including correspondence between the EPO and patent applicants or attorneys.²²

The EPO's "All documents" panel displays publicly available documents chronologically, with most documents becoming available one day after being sent or coded by the EPO.²³ This system also tracks oppositions, unitary patent effects, and Unified Patent Court opt-outs.²⁴

UK IPO Databases

The UK Intellectual Property Office provides several databases for accessing prosecution history. The Ipsum service offers access to prosecution file documents for GB patent applications published after 1 January 2008, including examination reports, specifications, claims, and correspondence with the IPO.²⁵ The IPO also maintains a searchable database of patent decisions from hearing officers dating back to 1998.²⁶

Prosecution History Estoppel

What It Is and When It Applies

Prosecution history estoppel is a legal doctrine that prevents patent holders from recapturing subject matter they surrendered during patent prosecution.²⁷ The doctrine recognises that when applicants make statements or amendments to secure patent allowance, they create a public record upon which competitors should be able to rely.²⁸

The Supreme Court in Warner-Jenkinson established that competitors may rely on prosecution history to estop patentees from recapturing subject matter surrendered by amendment as a condition of obtaining the patent.²⁹ This principle applies whether the surrender was explicit through amendments or implicit through arguments distinguishing prior art.³⁰

Festo Doctrine

The landmark Supreme Court case Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co. (2002) fundamentally reshaped prosecution history estoppel doctrine.³¹ The Court held that prosecution history estoppel may apply to any claim amendment made to satisfy Patent Act requirements, not just amendments made to avoid prior art.³²

However, Festo rejected the Federal Circuit's "complete bar" rule, instead establishing a rebuttable presumption approach.³³ The original Federal Circuit panel in 234 F.3d 558 (2000) had held that "any narrowing amendment made for reasons related to patentability effects a complete bar to the doctrine of equivalents for the amended claim element".³⁴ The Supreme Court explicitly rejected this absolute approach, reinstating the "flexible bar" rule that allows prosecution history estoppel to foreclose some, but not all, claims of equivalence depending on the circumstances.³⁵

Under this framework, estoppel creates a presumption that the patentee has surrendered the territory between the original claim and the amended claim.³⁶ The patentee can overcome this presumption by demonstrating that at the time of amendment, one skilled in the art could not reasonably have drafted a claim that would have literally encompassed the alleged equivalent.³⁷

The Festo Court identified specific circumstances where this showing might succeed: when the equivalent was unforeseeable at the time of the amendment, when the rationale underlying the amendment bore only a tangential relation to the equivalent in question, or when there was some other reason suggesting the patentee could not reasonably have been expected to have described the insubstantial substitute in question.³⁸

Following the Supreme Court's remand, the Federal Circuit in 304 F.3d 1289 (2002) was tasked with implementing the flexible bar approach and determining whether rebuttal determinations were questions of law or fact.³⁹ This established the modern framework for analysing prosecution history estoppel under a rebuttable presumption standard rather than an absolute bar.⁴⁰

Recent Developments: The Colibri Expansion

In July 2025, the Federal Circuit significantly broadened prosecution history estoppel doctrine in Colibri Heart Valve LLC v. Medtronic CoreValve, LLC.⁴¹ The court held that estoppel can be triggered by the simple cancellation of a closely related claim—even when the asserted claim itself was never amended.⁴²

In Colibri, the patentee had filed two independent claims differing only in deployment mechanism: one claiming "pushing" a heart valve from a sheath, another claiming "retracting" the sheath.⁴³ When the examiner rejected the "retracting" claim for lack of written description, the applicant cancelled it without amendment.⁴⁴ The Federal Circuit found this cancellation created prosecution history estoppel that barred doctrine of equivalents arguments regarding retraction-based devices.⁴⁵

This decision represents a substantive shift from requiring amendment of the particular asserted claim to applying estoppel when cancelled claims are "closely related" and involve "intertwined terminology".⁴⁶

Impact on Claim Construction

Statements Limiting Claim Scope

Prosecution history serves as intrinsic evidence in claim construction, ranking below the specification but above extrinsic evidence like dictionaries and expert testimony.⁴⁷ Under the Phillips v. AWH Corp. framework, courts must consult the intrinsic record—including prosecution history—to determine claim meaning as understood by one skilled in the art.⁴⁸

Statements made during prosecution can limit claim scope through several mechanisms. Applicants may explicitly define claim terms in responses to office actions, particularly when addressing indefiniteness or written description rejections.⁴⁹ These definitions become part of the permanent record and constrain later claim interpretation.⁵⁰

Disavowed Claim Scope

The prosecution history can also create "disavowal" of claim scope when applicants make "clear and unmistakable" statements surrendering particular interpretations.⁵¹ This exacting standard prevents patentees from recapturing meanings they disclaimed during prosecution.⁵²

Recent Federal Circuit decisions have somewhat relaxed this standard. In Focus Products Group International v. Kartri Sales Co., the court held that disavowal can occur through an applicant's failure to challenge examiner findings and by taking actions consistent with those findings, rather than requiring explicit statements.⁵³

Examiner Interviews

Examiner interviews present unique challenges for prosecution history analysis. Under MPEP 713, all discussions regarding application merits must be made of record.⁵⁴ Interview summaries often contain explanations of claim scope that supplement the written record, though the Federal Circuit has noted that prosecution history is "less useful" than the specification because patent prosecution involves negotiation and introduces ambiguities.⁵⁵

Impact on Infringement Analysis

Doctrine of Equivalents Limitations

Prosecution history estoppel most commonly affects infringement analysis by limiting doctrine of equivalents claims. The doctrine allows infringement findings even when accused products don't literally meet all claim terms, if there is "equivalence between the elements of the accused product and the claimed elements".⁵⁶

However, when prosecution history estoppel applies, it can bar equivalents claims entirely for the amended elements.⁵⁷ The Warner-Jenkinson Court established that equivalence analysis must be conducted on an element-by-element basis, with prosecution history potentially estopping individual elements while leaving others available for equivalents analysis.⁵⁸

Argument-Based Estoppel

Beyond amendment-based estoppel, the Federal Circuit recognises argument-based estoppel arising from statements made during prosecution.⁵⁹ When applicants distinguish prior art on particular grounds, these arguments can estop later equivalents claims that would encompass the distinguished subject matter.⁶⁰

The Federal Circuit has held that argument-based estoppel can apply when an applicant distinguishes prior art on a particular ground, even if the applicant also distinguishes the reference on other grounds.⁶¹ This doctrine prevents patentees from obtaining patents by arguing for narrow scope during prosecution, then enforcing them with broader interpretations in litigation.⁶²

Amendment-Based Estoppel

Amendment-based estoppel arises when applicants modify claims during prosecution, typically in response to prior art rejections.⁶³ Under Festo, this creates a rebuttable presumption that the patentee has surrendered the territory between the original and amended claims.⁶⁴

The strength of this presumption varies depending on the nature and reason for the amendment. Voluntary amendments may trigger estoppel, but the presumption may be more easily rebutted than for amendments made in direct response to prior art rejections.⁶⁵

What NOT to Do: Critical Mistakes in Prosecution History Analysis

These common errors can undermine your litigation position. We've seen each of these mistakes lead to adverse outcomes:

1. Ignoring the Full Prosecution History

The mistake: Reviewing only the final claims and immediately preceding office action response, rather than the complete file wrapper.

Why it fails: Earlier amendments and arguments may contain critical estoppel-triggering statements that don't appear in later documents. Courts consider the entire prosecution record when analysing estoppel.

Real consequence: Infringement theories that appear strong collapse when opposing counsel produces earlier prosecution statements that directly contradict your position.

2. Overlooking Related Patent Family Prosecution

The mistake: Limiting review to the asserted patent's prosecution history without examining continuations, divisionals, and foreign counterparts.

Why it fails: Statements made in related applications can sometimes be used to inform claim construction, particularly where claims share common ancestry or identical language.

Real consequence: Unexpected claim construction arguments emerge at late stages based on prosecution history from related patents you never examined.

3. Misunderstanding the Festo Rebuttals

The mistake: Assuming all prosecution amendments create absolute estoppel bars.

Why it fails: Festo established rebuttable presumptions, not absolute bars. The three specific circumstances (unforeseeability, tangential rationale, and other reasons) provide genuine opportunities to overcome presumptive estoppel.

Real consequence: Prematurely abandoning viable infringement theories that could survive estoppel analysis through proper rebuttal arguments.

4. Ignoring Cancelled Claims After Colibri

The mistake: Assuming only amendments to asserted claims matter for estoppel analysis.

Why it fails: The 2025 Colibri decision expanded estoppel to cancelled claims that are "closely related" to asserted claims. Cancelled claims now require careful analysis.

Real consequence: Doctrine of equivalents arguments are barred based on cancelled claims that were never directly asserted.

5. Failing to Document Investigation Methodology

The mistake: Conducting prosecution history research informally without documenting sources, search terms, and findings.

Why it fails: In litigation, you may need to demonstrate the thoroughness of your analysis and defend your conclusions under cross-examination. Informal research undermines credibility.

Real consequence: Expert opinions based on prosecution history analysis are challenged as incomplete or unreliable, potentially affecting admissibility.

6. Relying Solely on Patent Office Databases

The mistake: Assuming USPTO Patent Center or EPO Register contain complete prosecution records.

Why it fails: Some documents may be missing from online databases, particularly for older patents or complex prosecution histories involving interference proceedings, reexaminations, or appeals.

Real consequence: Missing documents surface during discovery that contradict your prosecution history analysis.

Technical Expert Review

What to Look For

When we review prosecution history as technical experts, several key categories demand attention. First, examine all claim amendments chronologically to understand how claim scope evolved and why changes were made.⁶⁶ Pay particular attention to amendments made in response to prior art rejections, as these most commonly trigger estoppel.⁶⁷

Second, analyse applicant arguments distinguishing prior art. Look for statements that characterise the claimed invention in ways that might limit scope or exclude accused devices.⁶⁸ These arguments often provide the clearest evidence of what the applicant considered outside the claimed scope.⁶⁹

Third, review examiner interview summaries, which may contain claim scope explanations not found in written responses.⁷⁰ While interview records are sometimes brief, they can reveal important applicant positions on claim meaning.⁷¹

Supporting Claim Construction

Prosecution history analysis should support claim construction positions by identifying intrinsic evidence of term meaning. Look for instances where applicants explicitly defined claim terms, particularly technical terms that might have specialised meanings in the relevant field.⁷²

Document any instances where applicants distinguished their invention from prior art based on specific claim limitations. These distinguishing statements can support narrow claim construction arguments and may establish prosecution history estoppel.⁷³

Identifying Estoppel Issues

Systematic prosecution history review should identify potential estoppel issues early in litigation. Create timelines showing claim amendments and the reasons provided for each change.⁷⁴ Map amended claim elements to accused device features to assess estoppel impact on infringement theories.⁷⁵

For each amendment, evaluate whether the three Festo exceptions might apply: unforeseeability of the equivalent, tangential relation between the amendment rationale and the equivalent, or other reasons why the patentee could not reasonably have described the equivalent.⁷⁶

Costs and Practical Realities

Understanding prosecution history analysis requires knowing what's actually at stake financially and strategically:

Cost of Professional Prosecution History Review

Basic file wrapper review:

• Single patent, standard prosecution: £3,000–£6,000
• Single patent, complex prosecution (RCEs, appeals): £6,000–£12,000
• Patent family review (3–5 related patents): £10,000–£20,000

Comprehensive estoppel analysis:

• Full estoppel mapping with claim charts: £8,000–£15,000
• Expert report on prosecution history: £15,000–£30,000
• Trial testimony preparation: £20,000–£40,000

Database access and document retrieval:

• USPTO Patent Center: Free
• EPO Register: Free
• UK IPO Ipsum: Free
• Commercial prosecution history services: £500–£2,000 per patent

Timeline Considerations

Initial prosecution history review: 2–4 weeks for thorough analysis Comprehensive estoppel assessment: 4–8 weeks including all related patents Expert report preparation: 6–12 weeks depending on complexity Response to opposing expert: 4–6 weeks

Strategic Value

For patent holders:

• Understanding estoppel limitations before filing suit prevents embarrassing retreats
• Early identification of problematic prosecution statements enables strategic claim selection
• Investment in prosecution history analysis is trivial compared to litigation costs

For accused infringers:

• Prosecution history often provides the most cost-effective defence
• Estoppel arguments can narrow or eliminate infringement allegations at summary judgement
• Technical expert support on prosecution history strengthens legal arguments

Cost-Benefit Analysis

The calculation:

• Cost of thorough prosecution history analysis: £10,000–£30,000
• Cost of missing critical estoppel issues: £200,000–£500,000+ in wasted litigation costs
• Cost of adverse claim construction from prosecution statements: Potentially case-determinative

Investing in proper prosecution history review before litigation decisions is essential. We consistently see cases where early prosecution history analysis would have prevented significant wasted expenditure.

UK vs US Jurisdictional Considerations

While prosecution history estoppel doctrine originated in US law, UK and European practitioners must understand its scope and limitations:

US Federal Courts

In the United States, prosecution history estoppel is a well-established doctrine applied by federal district courts and the Federal Circuit. The Festo framework with its rebuttable presumption approach governs all estoppel analyses.⁷⁷

US courts routinely examine prosecution history for both claim construction and infringement analysis. Expert testimony on prosecution history is common and often critical to case outcomes.⁷⁸

UK Courts and European Practice

The UK applies a different approach to patent claim interpretation under the Actavis "purposive construction" framework. While prosecution history is generally not given the same weight as in US practice, the Supreme Court in Actavis UK Ltd v Eli Lilly (2017) confirmed that prosecution history may be relevant in limited circumstances.⁷⁹

The European Patent Convention system similarly focuses on the claims and specification, with prosecution history playing a secondary role. However, EPO opposition proceedings create their own prosecution record that may be relevant to validity challenges.⁸⁰

Practical Implications for Multi-Jurisdictional Disputes

When patents are enforced across multiple jurisdictions:

Jurisdiction	Prosecution History Weight	Primary Focus
US Federal Courts	High – central to claim construction and estoppel	Festo doctrine, Warner-Jenkinson elements
UK Patents Court	Limited – may be relevant in certain circumstances	Specification and claims, purposive construction
EPO/UPC	Secondary – primarily for validity analysis	Technical teaching, opposition record

Strategic considerations:

• Prosecution statements that matter critically in US litigation may have limited impact in UK proceedings
• However, statements made to EPO during opposition may affect validity arguments in both jurisdictions
• Multi-jurisdictional enforcement requires understanding how prosecution history is treated in each forum

Safe vs Unsafe Prosecution History Analysis Approaches

Safe Approach	Unsafe Approach
Review complete file wrapper chronologically	Focus only on final office action and response
Examine related patent family prosecution	Limit review to asserted patent only
Document all amendments with reasons stated	Note amendments without analysing rationale
Consider cancelled claims post-Colibri	Ignore cancelled claims as irrelevant
Evaluate Festo rebuttal possibilities	Assume amendments create absolute estoppel
Cross-reference with claim charts	Analyse prosecution in isolation
Obtain original documents where possible	Rely solely on database summaries
Map arguments to specific claim elements	Treat arguments as applying generally

Strategic Implications

For Enforcement: Understanding Claim Scope Limitations

Patent holders must understand how prosecution history may limit their enforcement options. When we evaluate infringement claims, prosecution history review often reveals that certain infringement theories are foreclosed by estoppel.⁸¹ Early identification of these limitations allows for more realistic case assessment and settlement discussions.⁸²

The recent Colibri decision adds new complexity by potentially creating estoppel from cancelled claims, even without amendments to asserted claims.⁸³ Patent holders should review their prosecution history for cancelled claims that might be "closely related" to asserted claims and involve "intertwined terminology".⁸⁴

Consider whether prosecution history positions can be reconciled with planned infringement theories. When inconsistencies exist, evaluate whether the Festo exceptions might overcome presumptive estoppel.⁸⁵

For Defence: Leveraging Estoppel Arguments

Accused infringers can leverage prosecution history estoppel as a powerful defence tool. We recommend conducting comprehensive file wrapper review early in litigation to identify potential estoppel arguments.⁸⁶

Look for patterns where patentees made claims during prosecution that are inconsistent with their litigation positions. These contradictions can support both claim construction arguments and estoppel defences.⁵

The expanded estoppel doctrine from Colibri provides new defence opportunities by potentially creating estoppel from cancelled claims.⁷ Review the complete prosecution history for claims that were cancelled and evaluate whether they might estop current infringement theories.⁸

Recent developments in IPR estoppel also create strategic considerations. The Federal Circuit's clarification that IPR estoppel applies only to patents and printed publications—not "system prior art"—provides flexibility for defendants to raise alternative invalidity grounds in district court.⁹ Cases like Skyhawke Technologies v. Deca International demonstrate that various estoppel doctrines have limitations: issue preclusion may not apply between PTAB and district court proceedings due to different claim construction standards, and judicial estoppel only binds parties to positions they successfully advocated.⁸⁷

Conclusion

Patent prosecution history estoppel represents one of the most powerful doctrines in patent litigation, capable of foreclosing entire infringement theories regardless of their technical merit. The Festo decision established the modern framework, but recent developments like Colibri continue to expand estoppel's reach in ways that affect both patent holders and accused infringers.

Key Takeaways

The fundamental principles:

• Prosecution history creates a permanent public record of claim scope limitations
• Amendments made to secure patent allowance can trigger rebuttable estoppel presumptions
• Festo provides three specific circumstances for rebutting presumptive estoppel
• The 2025 Colibri decision expanded estoppel to cancelled "closely related" claims
• Argument-based estoppel can arise from statements distinguishing prior art

Immediate priorities when analysing prosecution history:

1. Obtain and review the complete file wrapper chronologically
2. Identify all claim amendments and the stated reasons for each
3. Analyse applicant arguments distinguishing prior art references
4. Review examiner interview summaries for claim scope explanations
5. Map amendments and arguments to accused product features

Critical mistakes to avoid:

• Ignoring the full prosecution history in favour of recent documents only
• Overlooking related patent family prosecution
• Assuming all amendments create absolute estoppel bars
• Ignoring cancelled claims after the Colibri decision
• Failing to document your investigation methodology

Cost-benefit analysis:

• Thorough prosecution history analysis: £10,000–£30,000
• Missing critical estoppel issues: £200,000–£500,000+ in wasted litigation
• Early prosecution history review is essential, not optional

For technical experts, mastering prosecution history analysis is essential to providing effective litigation support. The file wrapper contains a treasure trove of information about claim scope, inventor intent, and the boundaries of patent protection. However, accessing this information requires understanding both the legal framework and the practical mechanics of patent prosecution.

As patent law continues to evolve, prosecution history will remain a critical battleground in patent litigation. Understanding how to access, analyse, and leverage this record provides a significant strategic advantage in patent disputes.

If you're involved in patent litigation and need technical support for prosecution history analysis, we can help. Our technical analysis services support your legal team with file wrapper review, claim chart development, and estoppel assessment. We work alongside your solicitors and patent attorneys—providing the technical foundation they need while they handle the legal strategy.

This article is for informational purposes only and does not constitute legal advice. Consult qualified legal counsel before taking any enforcement or defence action based on prosecution history analysis.

Contact us to discuss how our technical analysis can support your litigation efforts.

---

Sources

Footnotes

1. Innovation Cafe US, "Understanding the USPTO File Wrapper: A Guide to Prosecution History and How to Read It," https://innovationcafe.us/understanding-the-uspto-file-wrapper-a-guide-to-prosecution-history-and-how-to-read-it ↩

2. Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., Ltd., 535 U.S. 722 (2002) ↩

3. Innovation Cafe US, "Understanding the USPTO File Wrapper: A Guide to Prosecution History and How to Read It" ↩

4. USPTO MPEP § 714, "Amendments, Applicant's Action [R-07.2022]," https://www.uspto.gov/web/offices/pac/mpep/s714.html ↩

5. Patent Challenges, "Federal Circuit Confirms that Disavowal of Claim Scope Must Be Clear and Unmistakable" ↩ ↩²

6. Innovation Cafe US, "Understanding the USPTO File Wrapper: A Guide to Prosecution History and How to Read It" ↩

7. PatentlyO, "Federal Circuit Expands Prosecution History Estoppel to Simple Claim Cancellations in Colibri Heart Valve" ↩ ↩²

8. Mondaq, "Federal Circuit: Cancellation Of Closely Related Claims Triggers Prosecution History Estoppel And Limits Infringement Scope" ↩ ↩²

9. Reuters, "Federal Circuit clarifies scope of IPR estoppel and resolves district court split in patent law," https://www.reuters.com/legal/legalindustry/federal-circuit-clarifies-scope-ipr-estoppel-resolves-district-court-split-2025-07-10/ ↩ ↩²

10. USPTO, "Manual of Patent Examining Procedure (MPEP)," https://www.uspto.gov/web/offices/pac/mpep/index.html ↩

11. 37 CFR § 1.111, "Reply by applicant or patent owner to Office action" ↩

12. USPTO MPEP § 713, "Interviews [R-07.2022]," https://www.uspto.gov/web/offices/pac/mpep/s713.html ↩

13. BitLaw, "MPEP 713.01: General Policy, How Conducted, November 2024," https://www.bitlaw.com/source/mpep/713-01.html ↩

14. Warner-Jenkinson Co. v. Hilton Davis Chemical, 520 U.S. 17 (1997) ↩

15. Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., Ltd., 535 U.S. 722 (2002) ↩

16. USPTO Patent Center, https://patentcenter.uspto.gov/ ↩

17. USPTO Open Data Portal, Patent File Wrapper, https://data.uspto.gov/patent-file-wrapper/search/details/17535118/application-data ↩

18. Innovation Cafe US, "Understanding the USPTO File Wrapper: A Guide to Prosecution History and How to Read It" ↩

19. USPTO Open Data Portal, Patent File Wrapper API, https://data.uspto.gov/apis/patent-file-wrapper/search ↩

20. Innovation Cafe US, "Understanding the USPTO File Wrapper: A Guide to Prosecution History and How to Read It" ↩

21. European Patent Office, "European Patent Register," https://www.epo.org/en/searching-for-patents/legal/register ↩

22. European Patent Register Help, "All documents," https://register.epo.org/help?lng=en&topic=Alldocuments ↩

23. European Patent Register Help, "All documents" ↩

24. European Patent Office, "European Patent Register" ↩

25. UK IPO, "Ipsum documents," https://www.ipo.gov.uk/p-ipsum/p-ipsum-documents.htm ↩

26. UK IPO, "Results of past patent decisions," https://www.ipo.gov.uk/pro-types/pro-patent/pro-p-os/p-challenge-decision-results.htm ↩

27. Warner-Jenkinson Co. v. Hilton Davis Chemical, 520 U.S. 17 (1997) ↩

28. Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., Ltd., 535 U.S. 722 (2002) ↩

29. Warner-Jenkinson Co. v. Hilton Davis Chemical, 520 U.S. 17 (1997) ↩

30. Casetext, "Warner-Jenkinson Co. v. Hilton Davis Chemical," https://casetext.com/case/warner-jenkinson-co-v-hilton-davis-chemical ↩

31. Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., Ltd., 535 U.S. 722 (2002) ↩

32. Cornell Law School, "FESTO CORP. v. SHOKETSU KINZOKU KOGYO KABUSHIKI CO., LTD., et al.," https://www.law.cornell.edu/supremecourt/text/535/722 ↩

33. Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., Ltd., 535 U.S. 722 (2002) ↩

34. BitLaw, "MPEP 714: Amendments, Applicant's Action, November 2024," https://bitlaw.com/source/mpep/714.html ↩

35. USPTO MPEP § 609, "Information Disclosure Statement [R-01.2024]," https://www.uspto.gov/web/offices/pac/mpep/s609.html ↩

36. Justia, "Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722 (2002)," https://supreme.justia.com/cases/federal/us/535/722/ ↩

37. Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., Ltd., 535 U.S. 722 (2002) ↩

38. Cornell Law School, "FESTO CORP. v. SHOKETSU KINZOKU KOGYO KABUSHIKI CO., LTD., et al." ↩

39. 37 CFR § 1.114, "Request for continued examination," https://www.law.cornell.edu/cfr/text/37/1.114 ↩

40. 37 CFR § 1.116, "Amendments and affidavits or other evidence after final action and prior to appeal," https://www.law.cornell.edu/cfr/text/37/1.116 ↩

41. Mondaq, "Federal Circuit: Cancellation Of Closely Related Claims Triggers Prosecution History Estoppel And Limits Infringement Scope," https://www.mondaq.com/unitedstates/patent/1683322/federal-circuit-cancellation-of-closely-related-claims-triggers-prosecution-history-estoppel-and-limits-infringement-scope ↩

42. Troutman Pepper, "Federal Circuit Ruling Broadens Reach of Prosecution History Estoppel to Include Canceled Claims," https://www.troutman.com/insights/federal-circuit-ruling-broadens-reach-of-prosecution-history-estoppel-to-include-canceled-claims/ ↩

43. PatentlyO, "Federal Circuit Expands Prosecution History Estoppel to Simple Claim Cancellations in Colibri Heart Valve," https://patentlyo.com/patent/2025/07/prosecution-estoppel-cancellations.html ↩

44. Morgan Lewis, "Federal Circuit Applies Prosecution History Estoppel Based on Claim Cancellation," https://morganlewis.com/pubs/2025/08/federal-circuit-applies-prosecution-history-estoppel-based-on-claim-cancellation ↩

45. Mondaq, "Federal Circuit: Cancellation Of Closely Related Claims Triggers Prosecution History Estoppel And Limits Infringement Scope" ↩

46. Troutman Pepper, "Federal Circuit Ruling Broadens Reach of Prosecution History Estoppel to Include Canceled Claims" ↩

47. Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005) ↩

48. CaseMine, "Federal Circuit Establishes Priority of Intrinsic Evidence in Claim Construction: PHILLIPS v. AWH CORP.," https://www.casemine.com/commentary/us/federal-circuit-establishes-priority-of-intrinsic-evidence-in-claim-construction:-phillips-v.-awh-corp./view ↩

49. Patent Challenges, "Federal Circuit Confirms that Disavowal of Claim Scope Must Be Clear and Unmistakable," https://www.patentchallenges.com/2019/03/federal-circuit-confirms-that-disavowal-of-claim-scope-must-be-clear-and-unmistakable/ ↩

50. Lexology, "The Clear and Unmistakable Standard for Applying Prosecution Disclaimer," https://www.lexology.com/library/detail.aspx?g=cee03157-b7e9-46c6-b049-68b5c2f4cbe8 ↩

51. Patent Challenges, "Federal Circuit Confirms that Disavowal of Claim Scope Must Be Clear and Unmistakable" ↩

52. CAFC Alert, "Disavowal of Claim Scope," https://cafc.whda.com/tag/disavowal-of-claim-scope/ ↩

53. Mondaq, "The Federal Circuit Expands Disclaimer Of Patent Scope During Prosecution," https://www.mondaq.com/unitedstates/patent/1697778/the-federal-circuit-expands-disclaimer-of-patent-scope-during-prosecution ↩

54. USPTO MPEP § 713, "Interviews [R-07.2022]" ↩

55. Oliff PLC, "Phillips v. AWH Corp.," https://www.oliff.com/wp-content/uploads/2020/11/Special-Report-Phillips-v-AWH-7-25.pdf ↩

56. Warner-Jenkinson Co. v. Hilton Davis Chemical, 520 U.S. 17 (1997) ↩

57. Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., Ltd., 535 U.S. 722 (2002) ↩

58. Supreme Court, "Warner-Jenkinson Co., Inc. v. Hilton Davis Chemical Co., 520 U.S. 17 (1997)," https://supreme.justia.com/cases/federal/us/520/17/ ↩

59. A.O. Shearman, "Applying The Doctrine of Argument-Based Estoppel, Federal Circuit Affirms District Court's Dismissal Of Infringement Claims," https://www.lit-ip.aoshearman.com/applying-the-doctrine-of-argument-based-estoppel- ↩

60. Mondaq, "Federal Circuit Clarifies Scope Of Estoppel Provision And Provides Guidance On 'Patentably Distinct'," https://www.mondaq.com/unitedstates/patent/1499612/federal-circuit-clarifies-scope-of-estoppel-provision-and-provides-guidance-on-patentably-distinct-claims ↩

61. A.O. Shearman, "Applying The Doctrine of Argument-Based Estoppel" ↩

62. Wikipedia, "Prosecution disclaimer," https://en.wikipedia.org/wiki/Prosecution_disclaimer ↩

63. Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., Ltd., 535 U.S. 722 (2002) ↩

64. Cornell Law School, "FESTO CORP. v. SHOKETSU KINZOKU KOGYO KABUSHIKI CO., LTD., et al." ↩

65. Justia, "Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722 (2002)" ↩

66. Innovation Cafe US, "Understanding the USPTO File Wrapper: A Guide to Prosecution History and How to Read It" ↩

67. Warner-Jenkinson Co. v. Hilton Davis Chemical, 520 U.S. 17 (1997) ↩

68. Patent Challenges, "Federal Circuit Confirms that Disavowal of Claim Scope Must Be Clear and Unmistakable" ↩

69. CAFC Alert, "Disavowal of Claim Scope" ↩

70. BitLaw, "MPEP 713.01: General Policy, How Conducted, November 2024" ↩

71. USPTO MPEP § 713, "Interviews [R-07.2022]" ↩

72. Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005) ↩

73. Lexology, "The Clear and Unmistakable Standard for Applying Prosecution Disclaimer" ↩

74. Innovation Cafe US, "Understanding the USPTO File Wrapper: A Guide to Prosecution History and How to Read It" ↩

75. Mondaq, "Federal Circuit: Cancellation Of Closely Related Claims Triggers Prosecution History Estoppel And Limits Infringement Scope" ↩

76. Cornell Law School, "FESTO CORP. v. SHOKETSU KINZOKU KOGYO KABUSHIKI CO., LTD., et al." ↩

77. Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., Ltd., 535 U.S. 722 (2002) ↩

78. Finnegan, "Using an Expert at a Markman Hearing: Practical and Tactical Considerations," https://www.finnegan.com/en/insights/articles/using-an-expert-at-a-markman-hearing-practical-and-tactical.html ↩

79. Actavis UK Ltd v Eli Lilly & Co 2017 UKSC 48 ↩

80. European Patent Convention, Article 69 and Protocol on Interpretation ↩

81. Troutman Pepper, "Federal Circuit Ruling Broadens Reach of Prosecution History Estoppel to Include Canceled Claims" ↩

82. PatentlyO, "Federal Circuit Expands Prosecution History Estoppel to Simple Claim Cancellations in Colibri Heart Valve" ↩

83. Mondaq, "Federal Circuit: Cancellation Of Closely Related Claims Triggers Prosecution History Estoppel And Limits Infringement Scope" ↩

84. Troutman Pepper, "Federal Circuit Ruling Broadens Reach of Prosecution History Estoppel to Include Canceled Claims" ↩

85. Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., Ltd., 535 U.S. 722 (2002) ↩

86. A.O. Shearman, "Applying The Doctrine of Argument-Based Estoppel" ↩

87. Lexology, "Can Claim Construction Arguments Impact Later Proceedings Due to Issue Preclusion or Judicial Estoppel?" https://www.lexology.com/library/detail.aspx?g=70201571-63cf-46ad-90f7-10d00407b7e0 ↩