From what I understand it prevents the "installation"/writing of a product into the ZODB (the products management part of the Control_Panel) and thus prevents conflict errors. If the product is already installed (e.g. by a client who is allowed to do so) then you can instantiate instances of your new product.
So if not clients do the installation, I would not be able to instantiate objects?
Simplistix - Content Management, Zope & Python Consulting
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