[Zope] Catalog Aware ZClass

Hello fellow Zopists, I want to create a catalog aware Zclass. I would like to include some specific indexable metadata when creating an instance of that object. So when I add an instance of that object it asks me for some information that gets indexed by ZCatalog to be searched later on. I have tried following the instructions given here: http://www.zope.org/Members/AlexR/CatalogAware But I noticed there is some information which may be outdated. It also suggests having to Patch CatalogAwareness.py I am not sure if this is still required? Or, where do I start? TIA! Scott