The European Commission released 8 documents relating to technical specifications for unique device identifiers (UDIs) for medical devices.
4 of them are relating to Basic UDI-DI, which manufacturers can use to connect and identify devices with the same purpose. These UDI-DI documents are from GS1, HIBCC, ICCBBA and IFA respectively. The other 4 documents would deal with UDI human readable interpretation (HRI) formats, including HRI qualifiers for UDI-DI, lot number, expiration date, serial number and manufacturing dates.
More details can be found in the EC website: