AI subject tested: Claude Sonnet 4.6 (web search on)
Question (paraphrased): Which central bank chaired the CPMI working group that produced the harmonised ISO 20022 data requirements for cross-border payments?
AI response:
"the specific sub-workstream chair for ISO 20022 harmonisation is attributed to the Federal Reserve Bank of New York in available public sources"
Regulator verbatim text:
"RBA press release (18 October 2023): 'The Reserve Bank of Australia chairs the CPMI working group that developed these requirements. Michele Bullock, RBA Governor, served as former Co-Chair of the CPMI Messaging Workstream.'"
Failure mode: misattributed
Substrate document: p_09_OTHER_Governance___which_institution_chaired_t_brief10.htm
This finding documents a confirmed hallucination by Claude Sonnet 4.6 (web search on) on a probe of the regulation. The model's response was tested against the regulator's verbatim primary text and classified as misattributed. Full per-finding context is available via the linked Citation ID.
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, Which central bank chaired the CPMI working group that produced the harmonised ISO 20022 data requirements for cross-bor [RLB-H-INT-BIS-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-Q004-Sonnet46], RegLegBrief AI Hallucination Research (June 11, 2026), https://reglegbrief.com/regulators/j1/int/BIS-CPMI/CPMI-ISO-20022-HARMONISATION-UPDATED-2026/practitioners/lawyers/finding/INT-BIS-CPMI-INT-001-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-v1-004/.
RegLeg Specialist Panel (2026). "Which central bank chaired the CPMI working group that produced the harmonised ISO 20022 data requirements for cross-bor — Practitioners — Lawyers." Citation ID: RLB-H-INT-BIS-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-Q004-Sonnet46. RegLegBrief AI Hallucination Research, published 2026-06-11. https://reglegbrief.com/regulators/j1/int/BIS-CPMI/CPMI-ISO-20022-HARMONISATION-UPDATED-2026/practitioners/lawyers/finding/INT-BIS-CPMI-INT-001-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-v1-004/
RegLeg Specialist Panel. (2026). Which central bank chaired the CPMI working group that produced the harmonised ISO 20022 data requirements for cross-bor [Hallucination finding RLB-H-INT-BIS-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-Q004-Sonnet46]. RegLegBrief AI Hallucination Research. https://reglegbrief.com/regulators/j1/int/BIS-CPMI/CPMI-ISO-20022-HARMONISATION-UPDATED-2026/practitioners/lawyers/finding/INT-BIS-CPMI-INT-001-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-v1-004/
@misc{reglegbrief_RLB_H_INT_BIS_CPMI_ISO_20022_HARMONISATION_UPDATED_2026_Q004_Sonnet46,
author = {RegLeg Specialist Panel},
title = {Which central bank chaired the CPMI working group that produced the harmonised ISO 20022 data requirements for cross-bor},
year = {2026},
publisher = {RegLegBrief AI Hallucination Research},
note = {Hallucination finding Citation ID: RLB-H-INT-BIS-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-Q004-Sonnet46},
url = {https://reglegbrief.com/regulators/j1/int/BIS-CPMI/CPMI-ISO-20022-HARMONISATION-UPDATED-2026/practitioners/lawyers/finding/INT-BIS-CPMI-INT-001-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-v1-004/}
}
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.