[Zope] Zope -- where is the order of initialization documented

I think I know how things are initialized, but I thought I'd verify my understanding by reading the documentation. I couldn't find anything about initialization execution order in the documents even though I am sure I read it somewhere. It's a question of where to put monkey patches for system code... A review of the archives didn't reveal much. If I want to change the behavior of, say, User.py by monkey patching, where's the right place to store them so they get executed in the right part of the initialization sequence?