If a folder doesn't itself contain a required object or method, I'd like to have another folder looked in instead. The fall-back folder won't necessarily (and often can't) be higher in the hierarchy, so acquisition doesn't seem to be a solution. Inheritance from a folderish class seems to be one solution, but I fear this might lead to an explosion of classes. The answer I think I need is to have a protoype mechanism (similar to that used in JavaScript and Self). A folder with the requirement to have its missing methods looked for elsewhere would be created as an instance of (say) PrototypedFolder with a pointer to the folder it wanted to use as a prototype. Does such a mechanism exist for Zope? Hamish Lawson University of St Andrews, Scotland ____________________________________________________________ Do You Yahoo!? Get your free @yahoo.co.uk address at http://mail.yahoo.co.uk or your free @yahoo.ie address at http://mail.yahoo.ie