Washington University Libraries use the Library of Congress classification system. For the most part, material for the study of classical antiquity is located in the classes PA "Classical Philology and Literature," and DE, DF, and DG, for general Mediterranean, Greek, and Roman history respectively. However, a substantial amount of relevant material is distributed elsewhere in the classification system, largerly according to the subject matter of the work.
Editions of works in the original languages are, as a rule, classified under call number PA, with occasional exceptions. Translations of classical literary works (e.g. poetry, drama) are classified under PA; however, translations into English of "nonliterary" works, such as history, philosophy, and geography are usually classified according to their subject matter--so, for example, translations of Plato and Aristotle will in the "B's". Classifications of commentaries and secondary literature on such works is a bit less consistent.
B108–708 Ancient Philosophy
BL700–820 Classical Religion and Mythology
BR160–240 Early History of Christianity
CN1–1100 Ancient Epigraphy
GT530–580 Ancient dress and costume
HC31–39 Ancient Economic History
HF355–381 History of Ancient Trade and Commerce
HT863 Ancient Slavery
JC51–93 Ancient Political Institutions & Theory
ML162-169 Ancient Music
N5320-5899 Fine Arts in Antiquity; NA210–340 Ancient Architecture; NA69–169 Ancient Sculpture; ND60–135 Ancient Painting, NK610–685 Ancient Decorative Arts; NK1180–1250 Ancient Decoration and Ornament; NK4645–4654 Greek & Roman Vases. Most of these titles are located at the Kranzberg Art and Architecture Library or at the West Campus Library.
P901–1099 Extinct Asian and European Languages
T16 Ancient Technology
U29–35 Warfare in Antiquity
Z105–115 Paleography, Z7016–7030 Bibliography of Classical Languages and Literature