Duty of Candor and IDS Practice Toolkit

By Casey Scott McKay · 2024-07-19

The duty of candor is the one prosecution obligation whose breach can render an entire patent family unenforceable, and it is administered day to day by docketing staff rather than by counsel. This toolkit sets out who is bound, what is material, and when disclosure must occur, then works the inequitable conduct standard after Therasense - but-for materiality plus specific intent to deceive, with the single most reasonable inference requirement - and the pleading standard from Exergen. It covers IDS mechanics and timing tiers, cross-citation across a family, the litigation overlap that generates most late disclosures, and remediation through supplemental examination. It closes with the collateral consequences: unclean hands, Walker Process antitrust claims, and exceptional case fees.

IP and Technology > Patent Counseling Transactions | Toolkit | Published 19 July 2024 - Updated 9 June 2025 | Casey Scott McKay - marksy.us

Summary. The duty of candor is the one prosecution obligation whose breach can render an entire patent family unenforceable, and it is administered day to day by docketing staff rather than by counsel. This toolkit sets out who is bound, what is material, and when disclosure must occur, then works the inequitable conduct standard after Therasense — but-for materiality plus specific intent to deceive, with the single most reasonable inference requirement — and the pleading standard from Exergen. It covers IDS mechanics and timing tiers, cross-citation across a family, the litigation overlap that generates most late disclosures, and remediation through supplemental examination. It closes with the collateral consequences: unclean hands, Walker Process antitrust claims, and exceptional case fees.

Keywords: duty of candor · rule 56 · information disclosure statement · IDS timing · IDS content · materiality · but for materiality · specific intent · Therasense · Exergen pleading · inequitable conduct · unclean hands · affirmative egregious misconduct · cross citation across a family · litigation overlap · supplemental examination · Walker Process fraud · exceptional case fees · prosecution records · remediation

Start Here

A patent is asserted. The defendant's answer pleads inequitable conduct, identifying a reference that was cited to the examiner in a sibling application and never cited in the patent at issue.

The sibling was prosecuted by a different attorney at a different firm four years earlier. Nobody at the current firm knew the reference existed. The docketing system tracked deadlines, not art.

That is the ordinary shape of an inequitable conduct allegation, and it is why the duty of candor is a systems problem rather than a legal one. The doctrine is demanding after Therasense v. Becton, Dickinson, and most allegations fail. But the ones that survive cost the entire family, and the discovery required to defeat one is expensive whether or not it succeeds.

This toolkit answers three questions.

Who is bound and what must be disclosed? 37 C.F.R. § 1.56 reaches everyone substantively involved, and materiality is broader than the litigation standard.
What does a breach actually require? But-for materiality and specific intent to deceive, each proved by clear and convincing evidence.
How is it prevented and remediated? Cross-citation discipline, litigation-prosecution coordination, and supplemental examination before an allegation is pleaded.

If you read only one thing, read Candor and Its Consequences. It works the Therasense standard and the practical disclosure decisions that follow from it.

Who Is Bound

The rule. 37 C.F.R. § 1.56 imposes on each individual associated with the filing and prosecution of an application a duty of candor and good faith, including a duty to disclose all information known to be material to patentability.

Who that covers. Each named inventor. Each attorney or agent who prepares or prosecutes the application. And every other person substantively involved in the preparation or prosecution who is associated with the inventor or the assignee.

"Substantively involved" reaches in-house counsel who direct prosecution, technical staff who supply information for responses, and business personnel who make decisions about the application. It does not reach everyone at the company.

The duty is individual. It is owed by persons, not by the company, and a company cannot discharge it centrally without ensuring that the individuals bound comply.

Duration. The duty continues until the application issues or is abandoned, and it applies to reexamination under 37 C.F.R. § 1.555.

No duty to search. The rule requires disclosure of information known to be material; it does not require a search. That distinction is important and frequently misstated.

But knowledge is imputed in practice. Information in the possession of a person bound by the duty is known to that person, and a system designed to prevent counsel from learning about art is a poor answer to an intent allegation.

Practitioner obligations run alongside. 37 C.F.R. § 11.18 imposes certification obligations on papers filed with the Office, and the professional conduct rules impose their own duties.

What Is Material

The rule's definition. Information is material where it is not cumulative and it establishes, alone or in combination, a prima facie case of unpatentability, or it refutes or is inconsistent with a position the applicant takes.

The litigation standard is narrower. Therasense v. Becton, Dickinson holds that for inequitable conduct, materiality is but-for: the claim would not have issued had the Office been aware of the reference, assessed under the preponderance standard and the broadest reasonable interpretation.

The gap between the two is deliberate. The regulatory duty is broader than the litigation consequence, which means an applicant should disclose more than the standard for unenforceability requires.

The exception. Therasense preserves an exception for affirmative egregious misconduct — the filing of an unmistakably false affidavit, for example — where materiality is presumed.

What is typically material. Prior art known to the inventors. Art cited in related applications, including foreign counterparts. Art cited in litigation involving related patents. Information about prior public use, sale, or offers. Inconsistent statements made elsewhere about the invention or the art. Information about inventorship.

Cumulative art is not material. But the judgment that a reference is cumulative is itself a judgment, and it should be recorded rather than made silently.

Inconsistent statements are the underappreciated category. Positions taken in a foreign prosecution, in litigation, or in a regulatory submission that contradict what is said to the examiner are material and are the source of a substantial share of allegations.

When in doubt, cite. Over-citation costs examiner attention. Under-citation costs an inequitable conduct trial. The asymmetry is not close.

Inequitable Conduct After Therasense

The two elements. But-for materiality and specific intent to deceive the Office. Both must be proved by clear and convincing evidence.

Specific intent. The accused infringer must show that the applicant knew of the reference, knew it was material, and made a deliberate decision to withhold it.

No sliding scale. Therasense abolished the practice of inferring intent from high materiality. The elements are separate.

The single most reasonable inference. Intent must be the single most reasonable inference able to be drawn from the evidence. Where multiple reasonable inferences exist, intent is not established.

Gross negligence is not enough. Kingsdown Medical Consultants v. Hollister established that, and Therasense reaffirmed it.

No duty to explain. The patentee need not offer a good faith explanation until the accused infringer meets its burden.

Pleading. Exergen v. Wal-Mart Stores requires inequitable conduct to be pleaded with particularity under Federal Rule of Civil Procedure 9(b): the who, what, when, where, and how of the material misrepresentation or omission, and sufficient allegations from which the court may reasonably infer that a specific individual both knew of the withheld information and withheld it with specific intent.

The consequence of a finding. The entire patent is unenforceable, and the taint can spread to related patents in the family through the doctrine of infectious unenforceability.

Aventis Pharma v. Hospira illustrates a case where both elements were found, and Ohio Willow Wood v. Alps South illustrates the analysis where the withheld information related to prior art testimony.

Regeneron Pharmaceuticals v. Merus shows a further exposure: litigation misconduct led the district court to draw an adverse inference of intent, and the patent was held unenforceable. Conduct during the case can supply the intent element.

IDS Mechanics

Content requirements. 37 C.F.R. § 1.98 requires a list of the information, legible copies of non-US patent documents and non-patent literature, and a concise explanation of relevance for non-English documents. US patents and published applications generally need not be supplied in copy.

The concise explanation. Required for information not in English, and it should be genuinely concise. An extensive characterisation of a reference creates prosecution history estoppel exposure and can itself become a materiality issue if it is inaccurate.

Timing tier one. 37 C.F.R. § 1.97 permits an IDS without fee or statement within three months of filing, or before the first office action on the merits.

Timing tier two. After that and before final action or notice of allowance, with either a statement or a fee.

Timing tier three. After final action or notice of allowance and before payment of the issue fee, with both a statement and a fee.

The statement. Certifies that the information was first cited in a communication from a foreign office not more than three months earlier, or that no item was known to any individual bound by the duty more than three months earlier.

After the issue fee. Consider withdrawal from issue, a request for continued examination, or a continuation. Where the reference is material, one of these is necessary; simply issuing the patent with the reference known and uncited is the fact pattern that generates allegations.

Quantity. There is no limit, and the Office considers what is submitted. Very large submissions can draw the argument that material art was buried, which is a recognised species of the allegation — the answer is a well-organised submission, not a smaller one.

Record the decisions. For each reference considered and not cited, a note on why — cumulative, not material, or already of record. That contemporaneous record is the best answer to a later intent allegation.

Foreign counterparts. Search reports and office actions from foreign counterparts are a principal source of material art, and the three-month statement window under 37 C.F.R. § 1.97 runs from the foreign communication.

Reexamination and reissue. 37 C.F.R. § 1.555 imposes the duty in reexamination, and reissue applications carry the ordinary duty.

Cross-Citation Across a Family

The single most productive control, and the one whose absence produces the classic allegation.

The problem. Art cited in one family member is frequently material to the others, and prosecution is frequently handled by different attorneys at different times.

The obligation. Where a person bound by 37 C.F.R. § 1.56 knows of material information, it must be disclosed in each application to which it is material. Knowledge does not compartmentalise by matter number.

Build the matrix. One row per application in the family; columns for art cited, foreign counterpart search reports, related litigation, and related proceedings. Reviewed at each filing and at each response.

Include foreign counterparts. Search reports from other offices routinely surface art the US examiner did not find, and the three-month window under 37 C.F.R. § 1.97 makes prompt handling necessary.

Include related litigation. Art cited in an invalidity contention against a family member is material to any pending application in the family. This is the highest-risk category because litigation counsel and prosecution counsel rarely share systems.

Include PTAB proceedings. Art asserted in an inter partes review of a family member is material to pending continuations.

Name an owner. The cross-citation matrix needs a person responsible for it, and in most portfolios that person is in the docketing function with a standing instruction to escalate.

Automate the trigger. A new office action, a new search report, or a new litigation filing should generate a review of the matrix rather than depending on someone remembering.

Document the judgment. Where art is reviewed and not cross-cited because it is cumulative, record why. That note is worth more in a later dispute than the citation would have been.

The Litigation Overlap

Where most late disclosures originate, and the coordination that prevents them.

The duty continues while any application is pending. A litigation against an issued patent frequently coincides with pending continuations in the same family, and the art asserted in that litigation is material to them.

Invalidity contentions are a disclosure event. When they arrive, the pending applications in the family need an IDS.

Expert reports and depositions can be too, where they disclose prior public use, sale, or knowledge not previously known.

Positions taken in litigation must be consistent with positions taken before the Office. A claim construction argued in court that contradicts what was argued to the examiner is the sort of inconsistency that supports both estoppel and materiality arguments.

Settlement agreements with licence terms can bear on secondary considerations and on prior art status, and they are sometimes material.

Name a coordinator. One person responsible for the flow of information from litigation counsel to prosecution counsel, with a standing instruction and a checklist.

Consider closing the family. Where litigation is active and continuations serve no strategic purpose, allowing them to issue or abandon removes the coordination burden entirely — a decision worth making deliberately rather than by drift.

Regeneron Pharmaceuticals v. Merus is the cautionary case: litigation misconduct supplied the intent inference that the withheld art alone would not have supported. Conduct in the case matters to the prosecution allegation.

Remediation

Supplemental examination. 35 U.S.C. § 257 permits a patent owner to request that the Office consider, reconsider, or correct information believed relevant to the patent. Where the Office concludes the information raises no substantial new question, or where reexamination is ordered and concluded, the information generally cannot thereafter be the basis for holding the patent unenforceable.

Its timing constraint. The protection does not apply to allegations already pleaded with particularity in a pending civil action, nor where the patentee has already received defined notice. Which means it must be used before the allegation, not in response to it.

Which means the audit has to be proactive. A portfolio review that finds a candor exposure while supplemental examination remains available is worth substantially more than one that finds it afterwards.

Cost. Substantial fees, including a further fee if reexamination is ordered. Reserve it for patents that matter.

The reexamination risk. If a substantial new question is found, reexamination follows and claims may be narrowed or cancelled, with intervening rights consequences under 35 U.S.C. § 307.

Reissue as an alternative. Where the problem is that claims would not have issued over withheld art, narrowing reissue under 35 U.S.C. § 251 addresses the but-for materiality element by producing claims that are patentable over it.

Late IDS in a pending application. Where the family is still pending, citing the reference now — with the 37 C.F.R. § 1.97 statement and fee — cures the exposure for that application and demonstrates good faith for the family.

Continuation practice as remediation. Filing a continuation, citing the art, and obtaining claims over it produces an enforceable patent even where the parent carries an exposure.

Document the remediation. What was found, when, what was done, and the reasoning. In a later dispute, a documented remediation is powerful evidence against specific intent.

Do not create the record casually. Internal correspondence about a candor exposure is discoverable if privilege is lost or the crime-fraud exception applies. Run the review under counsel. See Privilege and Work Product Toolkit for IP Matters.

Collateral Consequences

Inequitable conduct is the headline, and it is not the only exposure.

Unenforceability of the patent. The whole patent, not the tainted claims.

Infectious unenforceability. The taint can extend to related patents in the family where the misconduct has an immediate and necessary relation to their enforcement.

Unclean hands. Precision Instrument Manufacturing v. Automotive Maintenance Machinery supplies the equitable doctrine from which inequitable conduct descends, and it remains available for misconduct that does not fit the modern elements.

Exceptional case fees. 35 U.S.C. § 285, under the Octane Fitness v. ICON Health & Fitness standard, permits fee awards in cases that stand out from others. A finding of inequitable conduct is a strong candidate.

Walker Process antitrust. Walker Process Equipment v. Food Machinery & Chemical permits an antitrust claim where a patent was obtained by knowing and wilful fraud on the Office and the other antitrust elements are met. The standard is higher than inequitable conduct — common law fraud rather than but-for materiality plus intent — but the exposure is treble damages.

Professional consequences. 37 C.F.R. § 11.18 certifications and the professional conduct rules create individual exposure for practitioners.

Reputational and transactional. A patent with a pleaded candor allegation is harder to license, harder to sell, and discounted in diligence whether or not the allegation succeeds.

Discovery cost. Even a failing allegation produces depositions of prosecution counsel, production of the prosecution file, and a crime-fraud motion. That cost arrives whether or not the defence prevails.

Which is the practical argument for the programme. Not that the doctrine is easy to establish — after Therasense it is not — but that being able to defeat the allegation at the pleading stage under Exergen v. Wal-Mart Stores is worth a great deal, and that depends on a record showing the disclosure decisions were made deliberately.

Building the Programme

A written policy. Two pages: who is bound, what to disclose, when, and to whom. Distributed to inventors, in-house counsel, and outside firms.

Inventor onboarding. The invention disclosure form should ask for known prior art, prior public uses, prior sales or offers, and prior publications by the inventors. That question, asked once at disclosure, captures most inventor knowledge.

A standing instruction to outside counsel. Cross-cite within the family; forward foreign search reports promptly; escalate anything that might be inconsistent with a position taken.

The cross-citation matrix. Owned by docketing, reviewed at each filing and each response, covering family members, foreign counterparts, related litigation, and related PTAB proceedings.

Litigation-prosecution coordination. A named coordinator, a standing checklist, and a trigger on invalidity contentions, expert reports, and depositions.

A consistency check before filing responses. Positions asserted to the examiner checked against positions taken in litigation, in foreign prosecution, and in regulatory submissions.

Decision records. For every reference considered and not cited, a one-line note on why. This is the habit that produces the record which defeats an intent allegation.

Escalation for close calls. A named partner or in-house counsel decides, and the decision is recorded with reasoning.

Retention. Prosecution files, decision records, and the cross-citation matrix retained for the life of the patent plus the limitations period.

An annual audit. Sample applications and check whether cross-citation happened, whether foreign art was handled within the window, and whether decision records exist.

Training. Prosecution staff annually, inventors at onboarding, and litigation counsel on the coordination obligation.

Three Worked Situations

The sibling reference. Prosecuting a continuation, counsel finds a reference cited in the parent that was never cited in a second family member now pending. The reference is arguably material to that member's claims. The answer is straightforward: file an IDS in the pending application with the 37 C.F.R. § 1.97 statement and fee, record why it was not previously cited, and add the family to the cross-citation matrix. For the family member that already issued, consider whether the reference is but-for material to its claims and, if so, whether supplemental examination under 35 U.S.C. § 257 is warranted while it remains available.

The inconsistent argument. A response to an office action asserts that the art does not teach a particular feature. Litigation counsel, in a different matter, has taken a claim construction position implying the feature was well known. The inconsistency is material under 37 C.F.R. § 1.56. The fix is to reconcile the positions before filing the response, and where they cannot be reconciled, to disclose the inconsistent statement.

The late-arriving search report. A foreign office issues a search report citing three references, two weeks before the issue fee is due on the US counterpart. The three-month window under 37 C.F.R. § 1.97 permits an IDS with the statement and fee before issue fee payment. Missing that window means either issuing with known material art uncited — the fact pattern that generates allegations — or withdrawing from issue and filing a request for continued examination. The second is inconvenient; the first is a case.

Common Mistakes

No cross-citation across the family. The classic allegation, and entirely preventable by a matrix and an owner.

No litigation-prosecution coordination, so invalidity contentions never reach the pending continuations.

Foreign search reports handled slowly, losing the three-month statement window under 37 C.F.R. § 1.97.

Deciding a reference is cumulative without recording why. The decision may be right; the absence of a record makes it look like an omission.

Extensive characterisations in the concise explanation, creating estoppel exposure and a new materiality risk if the characterisation is inaccurate.

Burying material art in a very large submission, which is a recognised species of the allegation.

Inconsistent positions between prosecution, litigation, foreign prosecution, and regulatory filings.

Issuing with known material art uncited because the issue fee was already paid.

Treating Therasense as making the duty unimportant. The litigation standard tightened; the regulatory duty under 37 C.F.R. § 1.56 did not, and the cost of defending an allegation arrives regardless of the outcome.

Using supplemental examination too late, after the allegation is pleaded, when 35 U.S.C. § 257 no longer helps.

Conducting the internal review without privilege, creating a discoverable record of the exposure.

Litigation misconduct during the case, which after Regeneron Pharmaceuticals v. Merus can supply the intent inference the art alone would not support.

Defending the Allegation

For the patentee facing a pleaded inequitable conduct defence, the sequence is well established.

Attack the pleading first. Exergen v. Wal-Mart Stores requires particularity under Federal Rule of Civil Procedure 9(b): the specific individual who knew of the information, what the information was, where in the reference the material teaching lies, when and how it was withheld, and facts from which specific intent may reasonably be inferred. Most allegations as first pleaded fail one of those elements.

Insist on the individual. An allegation that "the applicant" withheld art does not identify the person bound by 37 C.F.R. § 1.56 who knew and decided.

Insist on but-for materiality. The pleading must allege facts showing the claim would not have issued had the Office known — not merely that the reference is relevant.

Insist on intent as a separate element. After Therasense there is no sliding scale, and materiality allegations do not supply intent.

On the merits, produce the decision record. A contemporaneous note explaining why a reference was treated as cumulative is the strongest available evidence that the omission was a judgment rather than a concealment.

Establish that other reasonable inferences exist. Intent must be the single most reasonable inference. Evidence of a heavy docket, a genuine cumulative judgment, or a reference that was overlooked rather than considered defeats that.

Prepare prosecution counsel. They will be deposed. Their preparation should include the file, the decision records, and the family history, and the deposition is frequently where the allegation is won or lost.

Anticipate the crime-fraud motion. An inequitable conduct allegation is the usual vehicle for challenging privilege over the prosecution file, and the threshold for in camera review is lower than for the exception itself.

Consider bifurcation. Inequitable conduct is tried to the court rather than a jury, and separating it can prevent the allegation from colouring the infringement and validity case.

Consider whether the reference actually invalidates. If it does not defeat the claims, but-for materiality fails, and an early prior art analysis can dispose of the defence.

And weigh the collateral exposures. 35 U.S.C. § 285 fees and, in the extreme case, a Walker Process Equipment v. Food Machinery & Chemical counterclaim.

Diligence Questions

Does a written candor policy exist, and who is bound under it?

Is there a cross-citation matrix, and who owns it?

How is foreign search report art handled, and within what timeframe?

How does litigation art reach pending applications, and who is the coordinator?

Are decision records kept for references considered and not cited?

Have any inequitable conduct allegations been made against any patent in the portfolio, and with what outcome?

Has supplemental examination under 35 U.S.C. § 257 been used, and on which patents?

Are there patents where known material art was not cited? This is the question a seller will not volunteer and a buyer should ask directly.

Are positions taken in prosecution consistent with positions taken in litigation and in foreign counterparts on the same family?

Are prosecution files complete and retained, including for patents prosecuted by prior firms?

Do any patents carry a family relationship to a patent found unenforceable? Infectious unenforceability travels.

The One-Page Position

Candor position — [portfolio], [date]. Applications pending: [N]; families with more than one pending member: [N]. Cross-citation matrix maintained by [owner], last reviewed [date]; families covered [N] of [N]. Foreign search reports received in the period: [N]; median days from receipt to IDS filing [N]; [N] filed within the three-month window under 37 C.F.R. § 1.97. Litigation overlap: [N] active matters against family members with pending continuations; coordinator [name]; invalidity contentions cited into pending applications on [N] of [N] occasions. Decision records: maintained on [N] per cent of references considered and not cited. Consistency checks performed on [N] responses. Inequitable conduct allegations: [N] pleaded, [N] dismissed at the pleading stage under Exergen, [N] pending. Supplemental examination under 35 U.S.C. § 257: [N] considered, [N] filed, [N] windows still open. Audit last completed [date]; [N] findings, [N] closed. Recommended actions: [assign an owner to the matrix / build the litigation trigger / file supplemental examination on X while the window is open / remediate the family Y cross-citation gap].

What Is Material, Worked Through Categories

The abstract definition is unhelpful in practice. These are the categories that actually arise.

Art known to the inventors. Publications they wrote, products they worked on previously, and competitor products they studied. Captured by asking at disclosure.

Art cited in a family member. The classic gap, addressed by the cross-citation matrix.

Art cited by a foreign office. Search reports and office actions from counterparts, with the three-month window under 37 C.F.R. § 1.97 running from the foreign communication.

Art asserted in litigation or a PTAB proceeding against a family member. Material to any pending application in the family.

Prior public use, sale, or offer. Activities by the applicant more than a year before filing engage 35 U.S.C. § 102, and information about them is material. This includes beta programmes, trade show demonstrations, and quotations to customers.

Inventorship information. Facts bearing on who conceived the claimed subject matter.

Inconsistent statements. Positions taken elsewhere — in foreign prosecution, in litigation, in a regulatory submission, in marketing materials — that contradict what is said to the examiner. Marketing claims about a product's novelty or its differences from prior products have supplied materiality in real cases.

Declaration support. Where a declaration is submitted under 37 C.F.R. § 1.132 to establish unexpected results or commercial success, the underlying data and any contrary data are material. Affirmative misrepresentation in a declaration is the Therasense egregious misconduct exception.

Information about the applicant's own products. Where the claims are argued to distinguish the art on a feature the applicant's own earlier product had, that is material.

Litigation settlement terms bearing on secondary considerations, in some circumstances.

What is not material. Cumulative art. Art already of record. Information not relevant to the claims as they stand. And information the applicant does not know — because 37 C.F.R. § 1.56 imposes no duty to search.

The judgment to record. For each category, the decision made and why. That record is the programme's entire output and its entire value.

Questions Clients Ask

Do we have to search for prior art? No. 37 C.F.R. § 1.56 requires disclosure of information known to be material; it does not require a search. Many applicants search anyway for other reasons.

If we do a search, do we have to cite what it finds? Yes, to the extent the results are material and not cumulative. That is not an argument against searching; it is an argument for handling the results properly.

Can we cite too much? There is no numerical limit, and the Office considers what is submitted. Very large submissions attract the argument that material art was buried, so organise the submission — but do not withhold to keep it small.

Should we explain each reference? Only where required for non-English documents, and then concisely. Extensive characterisations create estoppel exposure and their own materiality risk.

Our engineer knew about a competitor's product. Is that material? Potentially, and the question should be asked at invention disclosure rather than discovered in a deposition.

We demonstrated the invention at a trade show before filing. Information about that is material, and it also engages 35 U.S.C. § 102 directly.

Our foreign counsel got a search report last month. File the IDS now. The three-month window under 37 C.F.R. § 1.97 is what determines whether a statement suffices.

We already paid the issue fee and found material art. Withdraw from issue, or file a request for continued examination or a continuation. Issuing with known material art uncited is the fact pattern.

Does Therasense mean we can relax? The litigation standard tightened; the regulatory duty did not. And the cost of defending an allegation — depositions of prosecution counsel, production of the file, a crime-fraud motion — arrives regardless of the outcome.

Can we fix an old problem? Supplemental examination under 35 U.S.C. § 257, but only before an allegation is pleaded with particularity.

Who is actually at risk? Individuals, not the company. 37 C.F.R. § 11.18 and the professional conduct rules create practitioner exposure, and inventors sign declarations under 37 C.F.R. § 1.63.

What if a family member is held unenforceable? Infectious unenforceability can reach related patents where the misconduct has an immediate and necessary relation to their enforcement.

What This Costs

The policy. Two pages, written once, distributed.

The disclosure question at invention intake. Thirty seconds on a form that already exists.

The cross-citation matrix. Setup is a day for an established portfolio. Maintenance is minutes per filing, done by docketing rather than by counsel.

The litigation trigger. A checklist and a named coordinator. No systems purchase required.

Decision records. One line per reference not cited. The most valuable minute spent in the whole programme.

The annual audit. A day, sampling across families.

Against that: supplemental examination fees for a patent where an exposure is found, which are substantial but bounded.

And against that: defending an allegation. Prosecution counsel deposed. The file produced. A crime-fraud motion briefed. Expert testimony on materiality. A separate bench trial. Fee exposure under 35 U.S.C. § 285 if it succeeds, and a licensing and diligence discount on the patent whether it succeeds or not.

The programme is cheap. What it prevents is not.

A Closing Note

The doctrine and the practice point in slightly different directions, and it is worth being explicit about that.

Therasense made inequitable conduct genuinely hard to establish. But-for materiality, specific intent, no sliding scale, and the single-most-reasonable-inference requirement together mean that most allegations fail, and Exergen v. Wal-Mart Stores means many fail at the pleading stage.

None of that reduces the value of the practice, for three reasons. The regulatory duty under 37 C.F.R. § 1.56 is unchanged and is broader than the litigation standard. The cost of defending an allegation is incurred before the outcome is known. And the record that defeats the allegation — decision notes, a cross-citation matrix, a litigation coordinator — has to have been built years earlier, at a time when nobody was thinking about it.

Cite generously, record the judgments, connect the family, and connect litigation to prosecution. Four habits, none expensive, and together they convert the most dangerous allegation in patent practice into one that is dismissed on the pleadings.

The Four Habits

Cite generously. Over-citation costs examiner attention; under-citation costs a trial. The asymmetry decides every close call.
Record the judgment. One line per reference considered and not cited, with the reason. This is what makes an omission look like a decision rather than a concealment.
Connect the family. A matrix covering family members, foreign counterparts, and related proceedings, owned by a named person in docketing.
Connect litigation to prosecution. A coordinator and a trigger on invalidity contentions, so that art asserted against one patent reaches the applications still pending in its family.

A Suggested Reading Path

For the doctrine:

For the prosecution context:

For the litigation consequences:

Primary Authorities

| Authority | Proposition | |---|---| | 37 C.F.R. § 1.56 | Duty of disclosure; who is bound; materiality | | 37 C.F.R. § 1.97 | IDS timing tiers | | 37 C.F.R. § 1.98 | IDS content requirements | | 37 C.F.R. § 1.555 | Duty in reexamination | | 37 C.F.R. § 11.18 | Certifications to the Office | | 35 U.S.C. § 257 | Supplemental examination | | 35 U.S.C. § 282 | Presumption of validity; defences | | 35 U.S.C. § 285 | Exceptional case fees | | 35 U.S.C. § 102 | Prior art | | 35 U.S.C. § 103 | Obviousness | | Fed. R. Civ. P. 9 | Pleading fraud with particularity | | Therasense v. Becton, Dickinson | But-for materiality; specific intent | | Kingsdown Medical Consultants v. Hollister | Gross negligence insufficient | | Exergen v. Wal-Mart Stores | Pleading standard | | Aventis Pharma v. Hospira | Both elements found | | Ohio Willow Wood v. Alps South | Withheld prior art testimony | | Regeneron Pharmaceuticals v. Merus | Litigation misconduct and adverse inference | | Precision Instrument v. Automotive Maintenance Machinery | Unclean hands | | Walker Process Equipment v. Food Machinery | Antitrust claim from fraudulent procurement | | Octane Fitness v. ICON Health & Fitness | Exceptional case standard | | In re Spalding Sports Worldwide | Invention records privileged |

Forms and Templates

The Office Action Response Template is where the candor obligation is most often engaged, because the arguments made in a response are the positions that later-discovered information may be inconsistent with — and inconsistency is a materiality category practitioners underweight. Any response asserting that a reference teaches away, or that the art lacks a particular teaching, should be checked against what the file and the family actually contain before it is filed. The Portfolio Inventory Template is where the cross-citation matrix belongs: one row per application, with the family members, the art cited in each, the foreign counterparts, and the related litigations, so that a reference cited in one place is visible everywhere it is material. That matrix is the single control that would have prevented the scenario at the top of this toolkit. The Assignment Agreement Template matters indirectly, because the disclosure obligation that accompanies it — requiring inventors to disclose known prior art as well as inventions — is what brings inventor knowledge into the system in the first place.

Related Toolkits and Checklists

The Patent Prosecution Toolkit covers the prosecution mechanics into which IDS practice fits, and the Duty of Candor Checklist runs the obligations in order. The Patent Post-Issuance Correction Toolkit covers supplemental examination under 35 U.S.C. § 257 alongside the other remediation routes. The Privilege and Work Product Toolkit for IP Matters covers the crime-fraud exposure that an inequitable conduct allegation creates for the prosecution file. And the Patent Litigation Toolkit covers the defence, including the pleading challenge that disposes of most allegations early.