A library catalogue (an enumeration of all the resources of a library) is a register of all bibliographic items found in a library. A bibliographic item can be any information entity (e.g., books, computer files, graphics, relia, cartographic materials, etc.), that is considered library material (e.g., a single novel in an anthology), or a group of library materials (e.g., a trilogy), or linked from the catalog (e.g., a webpage) as far as it is relevant to the catalog and to the users (patrons) of the library.