On forums that allows editing your posts or topics for long times, or for admin and moderators to have an archive list for how many edits, who did i and the reasons why a post was edited for several times.
An option of how many items in the list can be shown
Ajaxed link list
better than popup of each edit, the reason for edit if available and who made it
It's always good to know who is editing your posts and when also for what reason.
Admins can keep an eye on the moderators and what they are doing.
cant think of any.