[Sacralletius]

Originally Posted by Rhyono So you'd like to be able to verify whether they have legitimately reached that rank?

Well, no, not really. Just through chat. They can post in chat: "I have "x amount of " fame points and "y amount of" infamy points. My current justice rank is "z".

What I meant by checking the "achievements", is not these ranks (from the addon) I'm referring to, but actual in game achievements.
So for instance, is possible to check through lua scripting if another player has the Silencer Dark Brotherhood achievement?

I don't know that much about actual lua scripting syntaxis, but that information could be used in this way:

Event OnDuelWon(Opponent)
    If Opponent.HasAchievement(Silencer) Then
        FamePoints = FamePoints + 20
        Victory.PlaySound()
        DisplayMessage(Another criminal has been brought to justice!)
    EndIf
End Event

I hope this makes sense. I was wondering whether there are any other events (OnStealItem, OnPickPocket, OnQuestCompleted(QuestID), etc) we could use to increase the values.