[Zope] form variables and **kw

Hi all, I have some questions. Say I have a external method/product method return_vars which I call from a form: def return_vars(self, var=None, **kw): return "var: %s, kw: %s" % (var,kw) Is it correct that any passed form variable besides "var" will get lost, i.e. that ZPublisher will _not_ marshall the other variables into the method call? If so, why? Is this a python limitation? I played around with co_varnames and python doesn't seem to offer a possibility to recognize **kw as something special. Where does this marshalling happen, in ZPublisher/mapply.py? TIA, oliver