[Zope3-Users] what is "__used_for__" attribute ?

[KLEIN Stephane]

Hi,

I wonder what is "__used_for__" attribute. I see this attribute in
"35.2 Step II: The Traverser" section of The Zope 3 Developers Book
(http://wiki.zope.org/zope3/traversal.html).

I never see this attribute in Philipp von Weitershausen's Web Component
Development with Zope 3.
I look for this in Zope 3 source code and this attribute is never used.
It's set but never used.

Someone can explain this ? If yes, can I add this answer in Zope 3 Faq
(http://wiki.zope.org/zope3/FAQ) ?

Thanks for your help,
Stephane