1. One or more computer storage media having stored thereon a data structure for storing data representing library description files associated with libraries, the data structures comprising: a first data field containing data representing one or more location elements, wherein one or more libraries are comprised of the one or more location elements; a second data field containing data representing a display format element for the one or more libraries; and a third data field derived from the first and second data fields representing a library description format of the one or more locations.