ADR-0087 exemption (no-migration-prescription): No key of any schema is added, removed or renamed: objects, object extensions, forms, flows, pages, views and autonumber formats keep their shapes and meanings. What moves is that a field an objectExtensions entry adds or re-declares is judged on the definition the registry serves. Each new refusal names a field whose served definition the runtime already refuses or misrenders (a text address, a file on an anonymous form, a gallery with no image field, a formula search column, an autonumber whose scope field may be blank or absent). There is no rewrite that keeps what the author meant; the author fixes the extension's definition or the reference, and the refusal names which.