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The BPMN 2.0 standard is very large and contains many objects that are unlikely to be used by an APEX developer. Like many BPMN workflow engine, Flows for APEX does not support every BPMN object. The diagram below shows a BPMN model containing all of the currently supported BPMN objects that you can use in your model.
In addition, the diagram above includes a Call Activity, which calls another diagram as part of its process.