A - General Works
AE - Encyclopedias
AI - Indexes
AY - Almanacs
B - Philosophy
BF - Psychology
BS - Bible
BX - Christian Churches
BX 8601-8695 - Mormon
BX8601 - Periodicals
BX8605 - Conferences
.A6 - Annual
.S3 - Semiannual
C - General History
CC - Archaeology
CD - Archives
CR - Heraldry
CS - Geneology
CT - Biography
D - Old World History
DA - Great Britain
DC - France
DD - Germany
DS - Asia
DT - Africa