Hi all, Here's what I want to do: By selecting a certain class as a base class for a new ZClass (eg MyBaseZClass), I want to have a management tab/page available to the Class definition in the Product where attributes can be added/ edited/deleted (basically access to an object list in MyBaseZClass). These are then created with instances of the ZClasses. Similar to propertysheets, but management of more complex objects than propertysheets provide. What I need is any information on how to define MyBaseZClass so that management tab appears in ZMI and so that properties set there will be created when an instance of the ZClass is created. Indeed, if people think ZClasses are even the way to go. They do provide the desired behaviour - user definition of class attributes via the ZMI which are then available to all instances of that class. Even better would be if there is already a simple solution that I've overlooked :) Any ideas/info/links would be greatly appreciated James Gilbert