[Zope] passing lists in forms

How do you destinguish between items in a list when submitting a form? I know to use "name:list" in the form, but when actually entering the data, should it be comma seperated, or return seperated or "['itemone'], ['itemtwo']" or what??? If I want to use say comma seperated items, does there need to be a bit of python to convert the text into a list? -ed-