If you report a battle or Duel to the campaign you are reporting a victory, there technically isn't a place for reporting losses in the current campaign.
As for injuries on duelling characters it becomes a burden on the individual which may reduce their chance of winning for a time. Otherwise it would simply be a defeat which you shouldn't report to the campaign. Though all duels must be recorded in some form in the character profile threads.
Check out the old
Campaign Guide, it has a small section on posting battles.
