An MLFB is a German acronym for Maschinen Lesbare Fabrikate Bezeichnung, which translates to Machine-readable Product Designation. 

The MLFB designation follows a Siemens-defined structure of numbers and letters, always located in defined positions, and indicates product type and business ownership.  The letters "I" and "O" are not permissible to avoid confusion with the digits "1" and "0".  An example is 3VA6225-6HN31-0DK0.

Essentially, an MLFB may be considered a product Catalog Number as assigned by Siemens in Europe.

Regional products are generally supported by localized Catalog Numbers, but some products - especially those in the Industrial space - are supported in the NAFTA market by their MLFB.