This is a simple addon made to return flagging behavior to what it was before WoD. While the scope of this addon has shrunk dramatically to within the walls of Stormwind or Orgrimmar, it's still pretty handy!
Currently while unflagged inside your capital city, if you attempt to attack or heal a flagged unit you will get an error message telling you to flag before attempting that action. Even with War Mode enabled! This absolutely grinds the flow of gameplay to a halt in intense city defense situations. With this addon you instead are simply flagged for PVP combat and sent on your merry way. Additionally, it will set you to unflag, if possible, in the next five minutes.
Simple, intuitive, and doesn't coddle. Just the way you remember from vanilla through to the end of MoP! Simply attempt attack an enemy inside your city walls and you will flag up for the occasion