Pin Parameters similar to those in the parameters in a Revision cloud wherein a user can input text describing why an object is pinned, who pinned it, etc.
Ideally, the text could appear as a "pop-up" when the pin is moused over. If the mouse over behavior is too challenging to code then the properties would show the "Comment" field (again, similar to a Revision) as well as other parameters regarding who pinned the object, when it was pinned, etc.
Alternatively/additionally a warning could appear when the pin state changes that would drive a user to the properties of the pin.