This will not be unique. The name of the author. A single author name is kept for each book. A list of subjects covered by the book. Subjects other than the one indicated by the classification code may be included in the list.
Subjects vary from edition to edition.
The name of the books publisher. A book which has two publishers is considered to be two different books and has two book nos. The normal library classification code. This does not vary from edition to edition. The physical location of the book in the library.