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Retail Banking × Risk — Singapore · published 2026-05-28 · methodology v2.1

Scope and exclusions of Annex 4D in MAS Notice 637

What the RLB Specialist Panel found

1. Scope and exclusions of Annex 4D in MAS Notice 637

  • Question (paraphrased to protect IP): What does Annex 4D of the consolidated MAS Notice 637 cover, and what category of items does it explicitly exclude from its scope?
  • Source regulation: MAS Notice 637 (Capital Adequacy Requirements for Banks in Singapore) (Regulator portal: https://www.mas.gov.sg)
  • What AI assistants typically say: The AI tool described Annex 4D as setting out credit conversion factors for off-balance sheet items within the leverage ratio framework, then qualified this characterisation by noting that other sources pointed toward the standardised approach for credit risk instead — without resolving the contradiction or indicating which framing was correct.
  • What the regulator actually says: No verified regulator excerpt was available at the time of testing. The precise scope of Annex 4D should be confirmed directly against the current consolidated text of MAS Notice 637 published on the MAS website.
  • Why the AI went wrong: The AI appears to have inferred the content of Annex 4D from the general structure of the Basel III framework rather than from the document itself. When its own search results contradicted the initial answer, the AI flagged the discrepancy as a verification note rather than correcting its primary response — leaving the user with an unresolved and likely incorrect characterisation.
  • Cited source(s):
Impact for this audience

A Risk team relying on the AI's Annex 4D characterisation could build an internal capital adequacy policy or leverage ratio methodology document that attributes credit conversion factor content to the wrong regulatory framework — either misclassifying it as a leverage ratio requirement when it belongs to the standardised approach for credit risk, or vice versa. This error would flow into model documentation, ICAAP materials, and potentially regulatory capital reporting. If MAS identifies the mischaracterisation during a supervisory review, the firm faces mandatory remediation, potential capital recalculation, and the reputational cost of a supervisory finding — all costs that the firm absorbs regardless of whether an AI tool was the proximate source of the error.

References — raw findings (per AI model)
This finding also affects
Next finding → Finding 2. Subject matter of Annex 6C in MAS Notice 637
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). "Scope and exclusions of Annex 4D in MAS Notice 637 — Retail Banking × Risk — Singapore." Citation ID: . RegLegBrief AI Hallucination Research, published 2026-05-28. https://reglegbrief.com/audiences/sectors/sg/retail_banking/risk/finding/q-NOTICE-637-CAPITAL-ADEQUACY-BANKS-2025-v1-017/
APA 7th edition 
RegLeg Specialist Panel. (2026). Scope and exclusions of Annex 4D in MAS Notice 637 [Hallucination finding ]. RegLegBrief AI Hallucination Research. https://reglegbrief.com/audiences/sectors/sg/retail_banking/risk/finding/q-NOTICE-637-CAPITAL-ADEQUACY-BANKS-2025-v1-017/
Bluebook / OSCOLA (US + UK legal) 
RegLeg Specialist Panel, Scope and exclusions of Annex 4D in MAS Notice 637 [], RegLegBrief AI Hallucination Research (May 28, 2026), https://reglegbrief.com/audiences/sectors/sg/retail_banking/risk/finding/q-NOTICE-637-CAPITAL-ADEQUACY-BANKS-2025-v1-017/.
BibTeX 
@misc{reglegbrief_,
  author    = {RegLeg Specialist Panel},
  title     = {Scope and exclusions of Annex 4D in MAS Notice 637},
  year      = {2026},
  publisher = {RegLegBrief AI Hallucination Research},
  note      = {Hallucination finding Citation ID: },
  url       = {https://reglegbrief.com/audiences/sectors/sg/retail_banking/risk/finding/q-NOTICE-637-CAPITAL-ADEQUACY-BANKS-2025-v1-017/}
}
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