Board Thread:General Discussion/@comment-26453983-20170501040959/@comment-168424-20170501221440

Another way to think of it is that if the red ! doesn't appear, your edit was probably acceptable to an admin or patroller.

FYI, you don't have to be an admin to clear the red !. There is also a rights group called Patrollers for those who can clear the mark. See Special:ListGroupRights.