MDCG 2019-1 : MDCG guiding principles for issuing entities rules on Basic UDI-DI – January 2019

This guide provides some clarification on the format of the basic UDI-DI. The basic UDI-DI should be a maximum of 25 characters long, so as not to deviate too much from the maximum length of the UDI-DI.  One of these characters must be a number or control character generated by an algorithm of the issuing entity. This algorithm shall be communicated to the Commission and the manufacturers.