This part of ISO/IEC 15909 defines an XML-based transfer format for Petri nets, which are defined conceptually and mathematically in part 1 of ISO/IEC 15909. This transfer format enables the exchange of Petri nets among different Petri net tools and among different parties. Moreover, this part of ISO/IEC 15909 defines some concepts and XML-based syntax for defining the detailed graphical appearance of Petri nets.The focus of this part of ISO/IEC 15909 is on the transfer format for Place/Transition Nets, High-level Petri Nets and Symmetric Nets. The presentation, however, is structured in such a way that it is open for future extensions, so that other versio