Currently any rental fee is issued each time a patron renews an item. In some cases this is unpractical e.g. when DVDs should get a rental fee for each renewals but ILLs only have a one off fee. I'm proposing that a new field "renewal fee" is created for each item type. I'll gladly try and aid any development, but since it will likely have to modify the database it will probably be a while until I can create any patch of my own since that is a bit out of my league.