Hello In the following piece of Python code for Zope: __ac_permissions__=( ('View management screens', ('manage_main',)), ('View', ('', 'index_html', 'update', 'show_source','view_image','picture',)), ('Change', ('manage_edit',), ('Manager',)), ) Could you tell me: 1) What does the first "empty" method ('') associated to the View permission mean? 2) Is the Manager method associated with the Change permission the class constructor for a Manager class which would represent the Manager role? 3) Why is Manager method needed in addition to the manage_edit one? 4) Why are there 2 tuples associated with the Change permission instead of having one tuple containing both the manage_edit and Manager methods? More generally, where can I find a REFERENCE doc (instead of a collection of how-tos or other items more or less related to the topic which is interesting you) in which such information (I mean developping Python code for Zope products) is __clearly__ defined? Thanks a lot in advance, Philippe