SWIFT is the network most custodians use to tell clients that an event exists and to take instructions back. Under ISO 15022 the corporate-action set is the MT56X series: MT564 notifies, MT565 instructs, MT566 confirms cash or stock, MT567 reports status, and MT568 carries narrative that will not fit the 564. MT599 is a free-format fallback, still seen on awkward warrant conversions, and dangerous because it is unstructured.
ISO 20022 — XML messages built from a shared business dictionary — is the successor. DTCC has offered it for US corporate actions since 2013, and SRD II shareholder-identification and proxy messages also ride on 20022. Disclosure (SIDR, SIDC, SIRE, SIRC, SIRS) and proxy (MENO, MECN, MENT, MEIN, MEIC, MEIS, MECO, MERD) message types sit alongside the classic 56X set.
Atlantic Horizon UCITS ICAV does not talk to Nippon Industrials or Thames Industrial directly. State Street sends the ICAV (and the Dublin administrator) an MT564 on each event, waits for an MT565 on anything with a choice, and confirms with an MT566 when cash or stock has moved. The Cayman sleeve rides the same SWIFT relationship.
Data scrubbing happens before any of this is booked: drop notices for securities you do not hold, compare duplicate custodian notices, and revive an event you ignored if the firm has since bought the stock. A Dublin NAV cannot be released on a SWIFT the books have not yet understood.
A simple cash dividend is a 564 on record date and a 566 on pay date. Thames Industrial’s scrip adds a 568 because the narrative will not fit the tags. Nippon’s split may never need a 565, because there is nothing to elect. If a 565 appears on the split, classification has already failed.
Scrubbing is the gate in front of the parser. Drop a 564 for a security the ICAV does not hold. Merge the State Street notice with the Japanese sub-custodian’s copy. Revive a notice you ignored if the manager has since bought the name. Dublin should never see a ticket for an event that is still two conflicting SWIFTs.