[Zope-dev] Why is it _setObject(), and why is it undocumented

I have a few tutorials / How_to's on zope.org. And sometimes I get some interresting mails because of that. Somebody asked me today why _setObject() has that name, as it is used in many products, and thus ought to be an interface method. And called something like "setObject()" or "manage_setObject()" And also he didn't understand why it wasn't documented anywhere. So why is that? does anybody know? regards Max M