Here's a thought. How does one effectively coordinate Ostracism in a City State with a population the size of Chicago?
Universal Repository listings are a starting point, but people need to know a person is an outlaw/ostracised/relevant isolating punishment here and people might not regularly check the repos, lest they interact with them and end up ostracised themselves. The ostracised person may resort to disguises or disguise magic to continue interacting with people anyways. Branding, tattoos, and amputation are removable via becoming. How then, does one coordinate Ostracism?
I've got an idea for a technological solution.
Per Trickery 5, it's possible to weave an illusion the size of a town that all can see. Make that an infrastructural working and incorporate automated mana analysis with a database of mystical signatures of the punished somehow fed into it. If the outlaw uses magic in town in an area within the illusion system's detection radius, their mystical signature shows up on the machine, which generates an illusory mark over the head of the outlaw/punished individual, warning people not to interact with them. Blurring the mystical signature needs at least Trickery 4.
Edit: I realized a way to get the data on mystical signatures into the illusion system. If there's no tech means of storing them use people. Mystery based memory enhancement is a thing(Mystery 4 near instant perfect recall and Mystery 3 memory palaces). Experience sharing magic can be used for them to know signatures they haven't seen personally.
Thoughts? Alternative Solutions?