While flags are only a minor part of the system,
they give us a great deal of power. We can allow folders to respond
to flags at particular stages, and also define activities that
trigger flags. One of the important aspects of flags is the ability
to define the data that is passed with a flag. This mechanism is
the primary mechanism for integrating processes, and the simplest
mechanism to allow external systems to interact with the Metastorm
BPM system.