1. For Alexander Library, all subject bibliographies are classed in a Z (bibliography) classification number.
2. For all libraries except Alexander, subject bibliographies are classed in a non-Z classification number.
3. Z (bibliography) numbers begin with the classification number Z1001. "Z" numbers Z4-Z1000.5 are subject classification numbers for the subjects Books (General), Writing, Paleography, Book Industries and Trade, and Libraries.
4. The East Asian Library collection classifies its subject bibliographies in non-Z classification numbers. It is an exception to this policy.