In my proposal: http://www.zope.org/Wikis/Interfaces/ExtensibleMetaData I mention interface object meta-data like pre/post conditions. This spurned a lot of interesting conversation, and I wanted to clarify some bits that I picked up from the thread. The proposal is not in any way trying to define what types of meta-data are interesting, this is, rightly, application dependent (for example, Zope would find security assertions interesting, other applications may not). The proposal is just proposing a mechanism for associating any kind of meta-data with an interface object. Dont get me wrong, the information on pre and post conditions was really interesting, especially Tim's description of Eiffel's particularly strong methedology that made me glad I don't work for the government. In the interest of clarifying what these interface objects are, I have created an Interface interface description: http://www.zope.org/Wikis/Interfaces/InterfaceInterface This describes interfaces, attributes and method objects and how they are used. I can forsee creating interface objects for these interface objects. The ones marked **Proposed** are the ones I am most interested in getting feedback on. Thanks! -Michel