AI Labs · Last updated 3 Jun 2026 · methodology v2.1 · Hallucination Register

Finding on 'Q002 Probe' for Claude Sonnet 4.6 with web search ON

RLB Citation ID: RLB-H-US-CFTC-SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025-Q002-Sonnet46

What the RLB Specialist Panel found

Finding on 'Q002 Probe' for Claude Sonnet 4.6 with web search ON

Question (paraphrased to protect IP): A partner-level client advisory on the December 2025 CFTC swap dealer rulemaking package is asked to cover the January 2026 correction notice. Which specific appendix was accidentally removed by the final rule as published, and what guidance does it contain?
AI's response: "The correction rectified a drafting error that would have unintentionally removed an appendix to the Commission's regulations that was not intended to be altered. The correction does not affect the substantive provisions of the rule."
Regulator's text: Appendix A to subpart H: "Guidance on the Application of §§23.434 and 23.440 for Swap Dealers That Make Recommendations to Counterparties or Special Entities." This appendix has been present since 2012. The Final Rule was not intended to alter appendix A in any way.
Why the AI went wrong: The model captured the structural framing of the correction, that a drafting error accidentally removed an appendix, but suppressed the content entirely: it did not name Appendix A, did not identify the subpart, and did not characterise the appendix's function as guidance on recommendations to counterparties and Special Entities. For a partner-level advisory, this response is operationally useless; the practitioner still does not know which appendix was affected or what obligations that appendix addresses. The qualifier that the correction "does not affect the substantive provisions" is accurate but serves as a deflection from the substance the question actually required.
Cited source(s):
https://www.lexology.com/library/detail.aspx?g=a14716ee-5a28-4e31-8adc-46d20e..., Pretextual

Impact for this audience

This failure is a qualifier-suppression pattern: the model characterised the correction's structure correctly (a drafting error accidentally removed an appendix) but omitted the specific content the question required — the appendix name, subpart, and the guidance function it serves for recommendations to Special Entities. The suppression is not a retrieval failure but a response-generation choice to stay at the structural level rather than commit to specific content, likely because the primary correction notice was not retrieved and the law-firm commentary cited did not name the appendix specifically.

References — raw findings (per AI model)

RLB-H-US-CFTC-SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025-Q002-Opus47 Claude Opus 4.7 (web search on)
RLB-H-US-CFTC-SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025-Q002-Sonnet46 Claude Sonnet 4.6 (web search on)

This finding also affects

← Previous finding Finding on 'Q004 Probe' for Claude Opus 4.7 with web search ON

Cite this finding

Each finding has a stable Citation ID (RLB-F-… for aggregated case-study findings, RLB-H-… for raw per-model hallucinations) — like a DOI, the ID always resolves to the canonical finding even if URLs change.

RLB Citation ID: RLB-H-US-CFTC-SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025-Q002-Sonnet46

Plain text Download

RegLeg Specialist Panel (2026). "Finding on 'Q002 Probe' for Claude Sonnet 4.6 with web search ON — AI Labs." Citation ID: RLB-H-US-CFTC-SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025-Q002-Sonnet46. RegLegBrief AI Hallucination Research, published 2026-06-03. https://reglegbrief.com/regulators/j3/US/CFTC/SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025/whitepaper/finding/US-CFTC-US-001-SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025-v1-002--sonnet-46-websearch/

APA 7th edition Download

RegLeg Specialist Panel. (2026). Finding on 'Q002 Probe' for Claude Sonnet 4.6 with web search ON [Hallucination finding RLB-H-US-CFTC-SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025-Q002-Sonnet46]. RegLegBrief AI Hallucination Research. https://reglegbrief.com/regulators/j3/US/CFTC/SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025/whitepaper/finding/US-CFTC-US-001-SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025-v1-002--sonnet-46-websearch/

Bluebook / OSCOLA (US + UK legal) Download

RegLeg Specialist Panel, Finding on 'Q002 Probe' for Claude Sonnet 4.6 with web search ON [RLB-H-US-CFTC-SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025-Q002-Sonnet46], RegLegBrief AI Hallucination Research (June 03, 2026), https://reglegbrief.com/regulators/j3/US/CFTC/SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025/whitepaper/finding/US-CFTC-US-001-SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025-v1-002--sonnet-46-websearch/.

BibTeX Download

@misc{reglegbrief_RLB_H_US_CFTC_SWAP_DEALER_BUSINESS_CONDUCT_DOCUMENTATION_2025_Q002_Sonnet46,
  author    = {RegLeg Specialist Panel},
  title     = {Finding on 'Q002 Probe' for Claude Sonnet 4.6 with web search ON},
  year      = {2026},
  publisher = {RegLegBrief AI Hallucination Research},
  note      = {Hallucination finding Citation ID: RLB-H-US-CFTC-SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025-Q002-Sonnet46},
  url       = {https://reglegbrief.com/regulators/j3/US/CFTC/SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025/whitepaper/finding/US-CFTC-US-001-SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025-v1-002--sonnet-46-websearch/}
}

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Every finding on this page compares an AI subject's account of the rule against the regulator's verbatim text from the regulator's own portal. Both are linked. Each delta, its root causes, and impact analysis are documented and published with immutable Citation IDs.