A set of documents including a letter or completed form indicating the drawer´s instructions (called a collection letter), and often accompanied by a draft or drafts, invoices, packing lists, and other documents as agreed by the drawer and drawee. Collections accompanied by documents restricting possession or ownership are called documentary, while those without such documents are called clean. Many collections are covered by the current Uniform Rules of Collections (URC) published by the International Chamber of Commerce. Since de URC is not a law, it must be specified in order to apply. However, it is in such common use that reference to it is often printed on the collection letterforms commonly used by banks.