BPMN Version

The graphical notation of Appian is complaint with BPMN 2.0 but the xml that Appian uses internally does not follow BPMN 2.0 completely. There are also some nodes defined by BPMN 2.0 that are not available in Appian. You can see the full BPMN 2.0 description here

In another discussion Malcolm Ross, deputy CTO from Appian, explain it. It is not possible to import/export BPMN 2.0 models from other BPMN 2.0 platforms directly into / from Appian.