In team-missions and team-PvP, the chat-window is very much spammed if you have the 'other hit other' option for messages permitted, active.
Disabling this gets rid of the spam, but if you are a pet-user, it means you can't see how hard your pet hits or how hard your pet gets hit.
Therefore, I suggest two new options:
'Pet hit other' - lets you see/not see your pet's damage to an opponent.
'Other hit pet' - lets you see/not see an opponent damaging your pet.
I hope this isn't so difficult to implement, considering the amount of options already in place.