The Yale Libraries uses both the Library of Congress (LC) classification system and, for older materials, the Yale Classification System.
For the most part, material for the study of classical antiquity is located in the LC classes PA "Classical Philology and Literature," and DE, DF, and DG, for general Mediterranean, Greek, and Roman history respectively. Yale Classification for ancient history is largely the same as the Library of Congress and in the Classics Library the books are shelved together. The equivalent of PA in the Yale Classification is G3-Gr. However, a substantial amount of relevant material is distributed elsewhere in the LC and Yale classification systems, largely according to the subject matter of the work.
Editions of classical works in the original languages are, as a rule, classified under call number PA (LC) and G (Yale), with some exceptions. Translations of classical literary works (e.g. poetry, drama) are classified under PA and G; 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 generally be in the "B's" as philosophy. Classifications of commentaries and secondary literature on such works is a bit less consistent.
In addition to the Classics Library, an extensive circulating collection of classical material is housed at Yale's Sterling Memorial Library (SML), also shelved using both the LC and Yale Classification systems . Additional classical reference works can be found in SML's Starr Reference Room. Material on classical art and architecture can also be found at the Haas Family Arts Library. Older and less frequently used material is located at the Library Shelving Faculty (LSF) and can be requested for pick up at many campus libraries, although not at the Classics Library.
B108–708 Ancient Philosophy
BL700–820 Classical Religion and Mythology
BR160–240 Early History of Christianity
CE21–46 Ancient Chronography
CE42–46 Greek & Roman Calendars
CJ201–1400 Ancient Numismatics
CN1–1100 Ancient Epigraphy
G82–88 Ancient Geography
G1033 Atlases of the Ancient World
GT530–580 Ancient dress and costume
GV17–35, 573 Ancient Sports and Games
HC31–39 Ancient Economic History
HD132–137 Ancient Economic History (Land)
HD4844 Labor in the Ancient World
HF355–381 History of Ancient Trade and Commerce
HN9–10 Ancient Social History
HQ13 Ancient Sexuality
HQ505–12 The Family in Antiquity
HQ1127–1139 Women in the Ancient World
HT863 Ancient Slavery
JC51–93 Ancient Political Institutions & Theory
KJA Roman Law
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
P901–1099 Extinct Asian and European Languages
R126–127 Ancient Medical Works
R135 History of Ancient Medicine
T16 Ancient Technology
U29–35 Warfare in Antiquity
Z105–115 Paleography, Z7016–7030 Bibliography of Classical Languages and Literature