EMERGO SUMMARY OF KEY POINTS: The Basic UDI-DI is the key identifier of a device in Eudamed, on certificates and on the Declaration of Conformity. Multiple UDI-DIs can be linked to a single Basic UDI-DI, while a UDI-DI must be linked to only one Basic UDI-DI. The UDI-DI must unambiguously identify a device in the distribution chain; any change that may confuse identification should result in a new UDI-DI. Manufacturers can now identify the data elements and formats for developing their databases in preparation of the introduction of UDI in Europe.