AC - Collections. Series. Collected works
AE - Encyclopedias
AG - Dictionaries and other general reference works
AI - Indexes
AM - Museums. Collectors and collecting
AN - Newspapers
AP - Periodicals
AS - Academies and learned societies
AY - Yearbooks. Almanacs. Directories
AZ - History of scholarship and learning. The humanities
For more detailed information, visit the Library of Congress Classification Outline.
AC - Collections. Series. Collected works
AE - Encyclopedias
AG - Dictionaries and other general reference works
AI - Indexes
AM - Museums. Collectors and collecting
AN - Newspapers
AP - Periodicals
AS - Academies and learned societies
AY - Yearbooks. Almanacs. Directories
AZ - History of scholarship and learning. The humanities