[Taler] How to trust an auditor?

[Florian Jung]

Hi!

As I read through the exchange setup manual, I found out that I can / 
need to(?) sign my exchange's keys with an auditor key. To me, this 
kinda makes sense in a real-world scenario, because I don't want to 
trust every single bank by its own, but I would like to trust, for 
example, "the euro-zone's auditor" (and every bank that is audited by them).

However, how do I configure this in my Android wallet? I found a list of 
exchanges, but is there also a way to set up a certain auditor as trusted?

Or did I misunderstand the purpose of these auditors?

Best regards,

Florian