Which specific appendix to 17 CFR Part 23 Subpart H was inadvertently removed by the December 2025 final rule and restored by the January 28, 2026 correction, and what guidance does it contain?
The model identified the general mechanics of the correction correctly but fabricated the Federal Register document number it cited as evidence — that identifier maps to no live document. More critically, it did not name the specific appendix or its content, producing a response that characterises the correction's structure without delivering the substance of what was asked. The fabricated citation suggests the model constructed plausible-sounding documentation scaffolding around a general understanding of the event rather than retrieving the primary correction notice.
This failure implicates two subsystems simultaneously: the citation-generation path produced a fabricated Federal Register document number rather than declining to specify, indicating the training corpus has secondary commentary on the correction without the primary document's structured metadata; and the retrieval layer did not surface the primary correction notice as a top result despite web search being active. The fabricated identifier (Doc. 2026-01712) would return no result at federalregister.gov — a model deployed in a compliance co-pilot context would deliver a dead citation with high confidence.
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?
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.
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.
Counsel relying on an AI summary of the January 28, 2026 correction notice would know a correction was issued but not which appendix it reinstated — meaning any opinion addressing the status of the suitability guidance under §§23.434 and 23.440 could be drafted without recognizing that Appendix A to Subpart H had a period of uncertain status. For swap dealers making recommendations to counterparties or special entities, that appendix is the operative interpretive authority; an opinion that doesn't register its momentary removal and restoration is missing a material fact in the compliance timeline.
The cited sources AI tools produced for this question included a fabricated URL, compounding the verification risk.
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.
RegLeg Specialist Panel, Finding#1 — January 2026 correction: Appendix A to Subpart H identity omitted [RLB-F-US-CFTC-SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025-Q002], RegLegBrief AI Hallucination Research (June 04, 2026), https://reglegbrief.com/regulators/j3/us/cftc/swap-dealer-business-conduct-documentation-2025/practitioners/lawyers/finding/US-CFTC-US-001-SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025-v1-002/.
RegLeg Specialist Panel (2026). "Finding#1 — January 2026 correction: Appendix A to Subpart H identity omitted — Practitioners — Lawyers." Citation ID: RLB-F-US-CFTC-SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025-Q002. RegLegBrief AI Hallucination Research, published 2026-06-04. https://reglegbrief.com/regulators/j3/us/cftc/swap-dealer-business-conduct-documentation-2025/practitioners/lawyers/finding/US-CFTC-US-001-SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025-v1-002/
RegLeg Specialist Panel. (2026). Finding#1 — January 2026 correction: Appendix A to Subpart H identity omitted [Hallucination finding RLB-F-US-CFTC-SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025-Q002]. RegLegBrief AI Hallucination Research. https://reglegbrief.com/regulators/j3/us/cftc/swap-dealer-business-conduct-documentation-2025/practitioners/lawyers/finding/US-CFTC-US-001-SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025-v1-002/
@misc{reglegbrief_RLB_F_US_CFTC_SWAP_DEALER_BUSINESS_CONDUCT_DOCUMENTATION_2025_Q002,
author = {RegLeg Specialist Panel},
title = {Finding#1 — January 2026 correction: Appendix A to Subpart H identity omitted},
year = {2026},
publisher = {RegLegBrief AI Hallucination Research},
note = {Hallucination finding Citation ID: RLB-F-US-CFTC-SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025-Q002},
url = {https://reglegbrief.com/regulators/j3/us/cftc/swap-dealer-business-conduct-documentation-2025/practitioners/lawyers/finding/US-CFTC-US-001-SWAP-DEALER-BUSINESS-CONDUCT-DOCUMENTATION-2025-v1-002/}
}