[Zope] Internal representation of permissions acquisition

[nwingfield at che-llp.com]

When looking into Zope's internal representation of permissions and so
forth, I found something strange...  Suppose, for example, I have checked
'Anonymous' for 'View' on a particular object, a new attribute called '
_View_Permission' is created in my object.

Here's the strange thing:
If I leave 'Acquire' checked, _View_Permission = ['Anonymous']
If I uncheck 'Acquire',       _View_Permission = ('Anonymous',)

Please confirm or deny my hypothesis that the sequence data type assigned
to a particular permission is the only way that Zope determines whether
permissions should be acquired or not.  It appears to me that the use of a
list is Zope's internal representation of a checked 'Acquire Permissions'
box, and the use of a tuple represents an unchecked 'Acquire Permissions'
box.