Clan troop specific requesting
Requesting specific troops are popular, especially for high level players.
Most people ask for certain troops (wiz or arch), some ask for anything, and few writes random messages.
However IT IS VERY EASY for people (trolls, noobs, jerks) to donate troops not requested. Send in that one wall breaker when requesting a dragon and NOBODY CAN TELL WHO IS TROLLING, unless they are logged in staring at their base.
Add a new feature to the clan castle's request troops, that allows clasher to check off which units can be donated in their request.
This will prevent random and unwanted donation.
Or
Add a recieved troops log to the clan castle.
This feature would show you who is donating what is not requested. Then people can tell that troll to stop donating what is not requested.