A - General Works

AC - Collected Works
AE - Encyclopedias
AG - Dictionaries & general reference works
AI - Indexes
AM - Museums
AP - Periodicals
AS - Academics & Learned Societies
AY - Yearbooks, Almanacs, Directories
AZ - History of Scholarship & Learning
  

B - Philosophy, Psychology, Religion

B - History & Systems of Philosophy
BC - Logic
BD - Speculative Philosophy
BF - Psychology
BH - Aesthetics
BJ - Ethics
BL - Religions, Mythology, Rationalism
BM - Judaism
BP - Islam, Bahaism, Theosophy
BQ - Buddhism
BR - Christianity (General)
BS - The Bible
BT - Doctrinal Theology
BV - Practical Theology
BX - Denominations & Sects
  

C - Auxiliary Sciences of History

CB - History of Civilization & Culture
CC - Archaeology (General)
CD - Diplomatics, Archives, Seals
CE - Chronology
CJ - Numismatics
CN - Epigraphy
CR - Heraldry
CS - Genealogy
CT - Biography (General)

L - Education

L - Education (General)
LA - History of Education
LB - Educational Theory & Practice
LC - Special Aspects
LD - U.S. Educational Institutions
LH - College & School Publications
LJ - Student Fraternities & Societies
LT - Textbooks (General)
  

M - Music

M - Music Scores
ML - Literature of Music
MT - Music Instruction & Study
  

N - Fine Arts

N - Visual Arts (General)
NA - Architecture
NB - Sculpture
NC - Graphic Arts (Drawing, Design, Illustration)
ND - Painting
NE - Print Media
NK - Decorative & Applied Arts
NX - Arts in general
  

P - Language & Literature

P - Linguistics
PA - Classical Philology (Greek & Latin)
PB - Modern European, Celtic Languages
PC - Romance Languages
PD - Old Germanic, Scandinavian Languages
PE - English Language
PF - Dutch, Flemish, German Languages
PG - Slavic Languages & Literature
PH - Finno-Ugrian, Basque Languages & Lit.
PJ-PL - Oriental Languages
PM - American Indian & Artificial Languages
PN - Literature, Literary History & Collections
PQ - Romance Literature
PR - English Literature
PS - American Literature
PT - German Literature
PZ - Children's Literature

A | B | C | D | E-F | G | H | J | K | L | M | N | P | Q | R | S | T | U | V | Z 
  

D - History (except America)

D - History (General)
DA - Great Britain
DAW - Central Europe
DB - Austria, Czechoslovakia, Hungary
DC - France
DD - Germany
DE - Mediterranean, Greco-Roman World
DG - Italy
DH-DJ - Netherlands, Belgium, Luxembourg
DJK - Eastern Europe
DK - Russia and Poland
DL - Northern Europe & Scandinavia
DP - Spain and Portugal
DR - Eastern Europe & Turkey
DS - Asia
DT - Africa
DU - Oceania, Australia, New Zealand
  

E-F - History: America & United States

E - America (General) & United States
F1-F975 - United States (local history)
F1001-F1140 - Canada
F1201-F1392 - Mexico
F1401-3799 - Central & S. American, Caribbean
  

G - Geography, Anthropology

G - Geography (General)
GA - Mathematical Geography, Cartography
GB - Physical Geography
GC - Oceanography
GE - Environmental Sciences
GF - Human Ecology
GN - Anthropology, Ethnology, Ethnography
GR - Folklore
GT - Manners & Customs
GV - Sports & Recreation

Q - Science

Q - Science (General)
QA - Mathematics
QB - Astronomy
QC - Physics
QD - Chemistry
QE - Geology
QH - Natural History, Biology
QK - Botany
QL - Zoology
QM - Human Anatomy
QP - Physiology
QR - Microbiology
  

R - Medicine

R - Medicine (General)
RA - Public Aspects of Medicine
RB - Pathology
RC - Internal Medicine
RD - Surgery
RE - Ophthalmology
RG - Gynecology & Obstetrics
RJ - Pediatrics
RK - Dentistry
RL - Dermatology
RM - Therapeutics, Pharmacology
RS - Pharmacy & Materia Medica
RT - Nursing
RV - Botanic, Thomsonian & Eclectic Medicine
RX - Homeopathy
RZ - Other Systems of Medicine
  

H - Social Sciences

H - Social Sciences (General)
HA - Statistics
HB - Economic Theory
HC - Economic History & Conditions
HD - Land, Agriculture, Industry
HE - Transportation & Communication
HF - Commerce
HG - Finance
HJ - Public Finance
HM - Sociology
HN - Social History
HQ - Social Groups
HS - Societies & Clubs
HT - Communities, Classes, Races
HV - Social Pathology, Criminology, Welfare
HX - Communism, Socialism, Anarchism
  

J - Political Science

J - Official Documents
JA - Collections & General Works
JC - Political Theory
JK - Constitutional History & Administration
JS - Local Government
JV - Colonization, Emigration & Immigration
JX - International Law, International Relations
  

K - Law

K - Law (General)
KF - United States Law

S - Agriculture

S - Agriculture (General)
SB - Plant Culture
SD - Forestry
SF - Animal Culture
SH - Aquaculture, Fisheries, Fishing
SK - Hunting
  

T - Technology & Engineering

T - Technology (General)
TA-TJ - Engineering
TK - Electronics & Electrical Engineering
TL - Motor Vehicles, Aeronautics, Astronautics
TN - Mining & Metallurgy
TP - Chemical Technology
TR - Photography
TS - Manufactures
TT - Handicrafts, Arts & Crafts
TX - Home Economics & Cooking
  

U - Military Science

  

V - Naval Science

  

Z - Book History, Library Sci., Bibliography