The circulation rules for each library are controlled by the data in the circulation map. The circulation map is a part of the circulation policies matches the User Profile with the Item Type to determine the loan period and billing structure for the circulation transaction.
The circulation rule consists of the loan period, fine rate, and maximum fine. An example is 21D-10D-5M for a 21 day loan, $.10 fine, and a $5 maximum fine.
The special rules for Deposit, Teacher, etc. cards are at the bottom of the circulation map. These rules apply to any user with that profile regardless of what library is being used.