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If a member of an order get's a writ on someone that defiles they can then yield that writ and then the Order can hire on the person that defiled. There are certain RP reasons why an order would only use members of the Ivory mark or Quisalis Mark to take on these writs. If the person you are trying to hire on is a member of the mark that you are trying to request then you are denied the ability to hire on the person.
We should look into better ways of managing both the Quisalis and Ivory marks since this new system has been put into place so that we don't see this kind of problem arising. You look at the Ivory mark as people that are championing the downtrodden and the Quisalis mark are assassins that will kill anyone just because they can. Having a member of the mark that goes around attacking shrines and then the order having no recourse against them seems to be an oversight of the system.