The following quote is taken from lstaffor's ZClass Properties HOW-TO: http://www.zope.org/Members/lstaffor/zProperties ----- In the field of object-orientented programming, the terms "class variables" and "instance variables" are often used for the data structures that are common to all methods of a class or of an object that is an instance of that class. ... For example, you may want a given data item to be a constant that is shared by all instances; the constant can be changed only by changing the class definition. ---- I'm confused about how class variables are implemented in Zope. For example, let's say I have a ZClass with instance variable "Subject" which is a list of keys into a dictionary "SubjectChoices". Rather than every instance maintaining a separate copy, SubjectChoices should be a class variable - all instances see the same dictionary. Any insights would be most appreciated. Cheers, Darran. -- Darran Edmundson [Darran.Edmundson@anu.edu.au]