Bind to an owner
A form binds a canonical operation, or edit binds the update operation for a record. The inferred arguments determine writable fields, types, defaults and required values. Explicit field selection can omit only already bound, defaulted or optional inputs; required unbound inputs must remain present. It cannot add authority or write protected fields. primary supplies the owning submit action; other checked actions remain distinct.
Use select for a reference only when the caller can currently read the selectable records and fields. File inputs use the upload/finalize/attach lifecycle; a browser-supplied URL is not a file reference. Validation messages belong beside their control, with the shared validation outlet available where the form places it.
Submission outcomes
A valid form can still be refused because permission, membership, row version, invariant or lock state changed after rendering. Preserve editable input and explain a conflict so the user can review and submit again. Do not retry a non-idempotent operation invisibly. See CRUD, actions, and input reference.
Compare your preserved form input with current values when a submission reports a conflict.