When you go to see who has attacked you if they have a shield the revenge button will be grey
Printable View
When you go to see who has attacked you if they have a shield the revenge button will be grey
http://i.imgur.com/98PtmjK.png
Unfortunately this idea has been ruled out in the sticky.
JustinQuote:
Graphical Interface Related:
*Separate tab in chat for troop requests
*Revenge list indicate online/shielded or currently attackable without having to click each person’s button
*Ability to hide certain attacks in battle logs