While editing a post in 7.1.1 all users can uncheck this option box preventing the edit time from showing up in the post.
Our moderators requested that only mods and admins be allowed to use this feature, preventing normal users from editing without leaving an edit timestamp. The "Reason for Edit:" field would still be available to members.
I was able to implement this change by adding a new template and changing code in the editpost.inc.php, checking for permission to decide which template to serve.
If others have a similar need, it would be great to have a control panel option to turn this feature on or off based on group permissions.