Blog about limits of extending BPMN 2.0 XML

[nikku]

What should we do?

• Create a blog post that describe extension points the BPMN 2.0 standard offers (bakes into the BPMN 2.0 schema).
• Describe, how that translates to extensibility (i.e. _Creating element bpmn:Foo is not a good idea`, instead ...).

Why should we do it?

The topic comes up in a regular fashion in the forum where users try to create elements like bpmn:foo and we need to argue why that is not a a good idea.