In 2000, there was a workshop [1] that should foster the definition of a standard transfer format for Petri nets as a satellite event of the annual ?Petri Net Conference? in Aarhus. As a result of this first workshop, after many other discussions and meetings, the Petri Net Markup Language (PNML) is about to be finally adopted as ISO/IEC 15909-2. Over the years, PNML has evolved and, unfortunately, there are many different intermediate versions and variants, that are still in use. With this paper, we would like to report on the final result and on PNML as it is defined in ISO/IEC 15909-2. This way, we hope to unify the different lines of PNML and advertise the use of ISO/IEC 15909-2.