I have written about this Active Directory property and how it can be used to identify the configuration of users for OCS 2007 R2. One of the keys is that if the number is an odd number, that means that the user has been configured for PIC access.
At my company, we have used this attribute for a couple of years to audit the users that have been enabled for PIC access.
Well, interestingly enough, when you move somebody from OCS 2007 R2 to Lync 2010, the attribute changes. The worst part is that that number changes from an even number (not enable for PIC) to an odd number when moved from OCS to Lync 2010. No, the permission doesn’t change, but the attribute does.
Well, this screwed up my process for identifying everyone that is PIC enabled. Thankfully, it is easier in Lync 2010. Whoo hoo!