Presentation Objects Declare No Custom Fields
Context
The designated-entity standard makes custom fields an explicit registration capability. These objects describe client presentation and have no metadata registrations.
Decision
Keep custom fields absent for shell objects. A placement links to a customer record type; it does not add fields to the navigation object.
Alternatives Considered
Configurable fields on menu or application presentation would require a separate product designation.
Consequences
Shell screens remain purpose-built. Any future field capability needs the recorded designation and registration changes required by the existing standard.