AI Hallucination Research › Regulators › Global standard-setters › INT › BIS-CPMI › CPMI-IOSCO-PFMI-2012 › White paper › Detail › Finding
AI Labs · published 2026-05-29 · methodology v2.1

Claude Sonnet 4.6 with web search

What the RLB Specialist Panel found
  • Question (paraphrased to protect IP): What specific text, assessment ratings terminology, or paragraph cross-references appear in the IOSCO co-published version of the CPMI-IOSCO disclosure framework and assessment methodology for financial market infrastructures?
  • AI's response: "I do not have verbatim access to the PDF at https://www.iosco.org/library/pubdocs/pdf/IOSCOPD396.pdf… I cannot provide specific verbatim text, exact thresholds, paragraph numbers, or precise named entities from the IOSCOPD396 PDF itself."
  • Regulator's text: [Not provided — verbatim-access question]
  • Why the AI went wrong: The model correctly declined to produce verbatim content from a PDF it acknowledged it could not access. The refusal is appropriately scoped. The cited URL maps to the inaccessible PDF — the same pattern of citing acknowledged-inaccessible sources seen across this model's verbatim-access findings, which represents a mild but consistent presentation inconsistency.
  • Cited source(s):
  • https://www.iosco.org/library/pubdocs/pdf/IOSCOPD396.pdf — Pretextual
Impact for this audience

Citation-alongside-refusal on the IOSCO disclosure framework and assessment methodology. Combined with finding 9 (where Opus 4.7 miscounted the rating scale categories), this finding establishes that the assessment methodology document is not reliably accessible to either model — which means any model-produced compliance assessment against PFMI standards is operating on reconstructed rather than retrieved criteria.

← Previous finding Finding 21. Claude Sonnet 4.6 with web search
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.

Plain text 
RegLeg Specialist Panel (2026). "Claude Sonnet 4.6 with web search — AI Labs." Citation ID: . RegLegBrief AI Hallucination Research, published 2026-05-29. https://reglegbrief.com/regulators/j1/int/bis-cpmi/cpmi-iosco-pfmi-2012/whitepaper/finding/INT-BIS-CPMI-INT-001-CPMI-IOSCO-PFMI-2012-v1-l3-027--sonnet-46-websearch/
APA 7th edition 
RegLeg Specialist Panel. (2026). Claude Sonnet 4.6 with web search [Hallucination finding ]. RegLegBrief AI Hallucination Research. https://reglegbrief.com/regulators/j1/int/bis-cpmi/cpmi-iosco-pfmi-2012/whitepaper/finding/INT-BIS-CPMI-INT-001-CPMI-IOSCO-PFMI-2012-v1-l3-027--sonnet-46-websearch/
Bluebook / OSCOLA (US + UK legal) 
RegLeg Specialist Panel, Claude Sonnet 4.6 with web search [], RegLegBrief AI Hallucination Research (May 29, 2026), https://reglegbrief.com/regulators/j1/int/bis-cpmi/cpmi-iosco-pfmi-2012/whitepaper/finding/INT-BIS-CPMI-INT-001-CPMI-IOSCO-PFMI-2012-v1-l3-027--sonnet-46-websearch/.
BibTeX 
@misc{reglegbrief_,
  author    = {RegLeg Specialist Panel},
  title     = {Claude Sonnet 4.6 with web search},
  year      = {2026},
  publisher = {RegLegBrief AI Hallucination Research},
  note      = {Hallucination finding Citation ID: },
  url       = {https://reglegbrief.com/regulators/j1/int/bis-cpmi/cpmi-iosco-pfmi-2012/whitepaper/finding/INT-BIS-CPMI-INT-001-CPMI-IOSCO-PFMI-2012-v1-l3-027--sonnet-46-websearch/}
}
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