AssignedBy for codes and identifiers, e.g. for transport units

[larsolofsson]

Currently in 4.0.0 for transport units, detailCode is assigned by Supplier and identifier is assignedBy LogisticsSupplier or Supplier.
Currently no agency is specified, e.g. for identifiers of railcars.
How to handle this in 5.0.0?

Currently schemas in 4.00 for example for transport units.

                              detailCode:
                                type: object
                                unevaluatedProperties: false
                                required:
                                  - value
                                  - assignedBy
                                properties:
                                  value:
                                    type: string
                                    minLength: 1
                                  assignedBy:
                                    type: string
                                    enum:
                                      - Supplier

                           identifier:
                                type: object
                                unevaluatedProperties: false
                                required:
                                  - type
                                  - value
                                properties:
                                  type:
                                    type: string
                                    enum:
                                      - ContainerID
                                      - CassetteID
                                      - ISO6346ContainerNumber
                                      # Don't use `assignedBy` with ISO6346ContainerNumber!
                                      - LicencePlateNumber
                                      - RailCarID
                                      - RFTagSerialNumber
                                      - SealNumber
                                      - TrailerID
                                      - VesselUnitID
                                  value:
                                    type: string
                                    minLength: 1
                                  assignedBy:
                                    type: string
                                    enum:
                                      - LogisticsSupplier
                                      - Supplier
                                  countryCode:
                                    type: string
                                    minLength: 2
                                    maxLength: 2