[Zope] Private Products

[Antonio Beamud Montero]

Hello all:
I'm newby with zope... I want create a Product for example named
"Factory" that includes another Products like Machines, Tasks, etc...
But I don't want that these Products (Machines, Tasks, etc) to be
"addables" in the Add List, only the Factory... How I can do this?
It's posible?

For now, I have created a Product Factory and a normal python class
named Machines, but I don't want this...

Thanks...