CMMN Task category

I can see the TaskInfo (and therefore Task) interfaces contain a getCategory() method, and documentation says “This is an optional field and allows to ‘tag’ tasks as belonging to a certain category.”, which is exactly what I need.
However, how do I set the category to a task? The modeler doesn’t seem to provide a field for category, but is there an element or attribute that I can add to the XML definition that maps to this field?

Found the answer for everybody interested, it’s the flowable:category attribute in the humanTaks (or any Task I guess) tag.

Still, I couldn’t find a definition of all the flowable extension attributes for CMMN.