Golden tablets with the seal of the ruler that issued the pass and the seal and name of who it was issued to. About the size of your palm of solid intricately etched gold. The holder of the tablet is backed by the authority of the king to make any required purchases on credit or enter any place they deem necessary. A very powerful token indeed.
No one is allowed to do harm to those of Highest/ Imperial rank, those of the Imperial household or those related within two steps of blood. The second tradition is an executioner must be of a higher rank than those he executes. This leads to "issues" when someone tries to harm a member of the Imperial clan or when these members are subversive. Such people are often killed by the being chained under a giant bell. They die within a day or so from the vibration, but they die untouched by Human hands.