Proposed motion to add the following comment to Device.serialNumber ""While a serial number is a type of identifier, in the context of devices for which a UDI is required, thus a serial number may be part of the production identifier, it is more informative to have the serial number as a dedicated attribute together with the other UDI production identifier.  When the device is not subject to including the UDI (e.g., its presence and exchange is not mandated by local regulatory requirements or specific use case at hand), thus the concept of production identifiers is not relevant as a set, it remains helpful for consistency to still use Device.serialNumber rather than using Device.identifier with an appropriate type.  Systems that do not realize an identifier is a serial number may place it in Device.identifier or if the identifier.system is known for the serial number, it may also be populated in the Device.identifier as a globally unique id_."_