Bug 24865 made it possible to use a notice to replace the default wording of the description for overdue fines. It would be helpful to expand that functionality to all debit types, both system-defined and local. It might make more sense to put this within the Debit Type setup than to continue using notices, though. These custom descriptions would allow Template Toolkit as notices do, however, for formatting, logic, and value transformation -- for example, one library wants the description to tell what portion of the fee goes to local tax.