Which central bank chaired the CPMI working group that produced the harmonised ISO 20022 data requirements for cross-border payments?
The model attributed the working-group chair role to the Federal Reserve Bank of New York — a higher-frequency institution in CPMI-adjacent content — rather than the Reserve Bank of Australia, which holds the published chair role and whose Governor served as Co-Chair of the relevant workstream. The hedge "in available public sources" is present but does not prevent the wrong attribution from being stated as the model's answer. This is a multi-body attribution failure where the less-frequently-cited institution holds the named role and the model substituted the more-frequently-cited institution from the same domain.
This failure implicates training-data density for working-group chair attribution across multi-body CPMI frameworks. The RBA press release (October 2023) naming the Reserve Bank of Australia as working-group chair exists within any plausible training window, but the model substituted the Federal Reserve Bank of New York — a higher-frequency institution in CPMI-adjacent content. The hedge 'in available public sources' signals the model detected uncertainty but did not prevent the wrong attribution from being stated.
The calibration signal for multi-body institutional role questions — where the correct answer belongs to a lower-frequency institution — is not sufficient to hold against the frequency prior.
A lawyer who cites the Federal Reserve Bank of New York — and a named individual there — as the chair of the CPMI ISO 20022 working group has put a fabricated institutional attribution into a client-facing document. The Reserve Bank of Australia chairs the group; no named individual at the Federal Reserve holds that role.
In an opinion letter, regulatory submission, or client briefing, that error is a credibility failure that surfaces the moment a counterparty checks the BIS or RBA primary source — and it is not the kind of error that can be characterised as a reasonable interpretive difference.
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 — Wrong central bank and fabricated individual named as CPMI working group chair [RLB-F-INT-BIS-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-Q004], RegLegBrief AI Hallucination Research (June 04, 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). "Finding#1 — Wrong central bank and fabricated individual named as CPMI working group chair — Practitioners — Lawyers." Citation ID: RLB-F-INT-BIS-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-Q004. RegLegBrief AI Hallucination Research, published 2026-06-04. 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). Finding#1 — Wrong central bank and fabricated individual named as CPMI working group chair [Hallucination finding RLB-F-INT-BIS-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-Q004]. 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_F_INT_BIS_CPMI_ISO_20022_HARMONISATION_UPDATED_2026_Q004,
author = {RegLeg Specialist Panel},
title = {Finding#1 — Wrong central bank and fabricated individual named as CPMI working group chair},
year = {2026},
publisher = {RegLegBrief AI Hallucination Research},
note = {Hallucination finding Citation ID: RLB-F-INT-BIS-CPMI-ISO-20022-HARMONISATION-UPDATED-2026-Q004},
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/}
}