Library of Congress Classification System
A - General Works
| AC | 1-199 | Collections, Series, Collected Works |
| 1-195 | Collections of Monographs, Essays, etc. | |
| 801-895 | Inaugural and Program Dissertations | |
| 901-995 | Pamphlet Collections | |
| 999 | Scrapbooks | |
| AE | 1-90 | Encyclopedias (General) |
| AG | 1-600 | Dictionaries and Other General Reference Works |
| 1-90 | Dictionaries, Minor Encyclopedias | |
| 103-190 | General Works, Pocketbooks, Receipts, etc. | |
| 195-196 | Questions and Answers | |
| 240-243 | Wonders, Curiosities | |
| 250 | Pictorial Works | |
| 305-313 | Notes and Queries | |
| 500-551 | Clipping Bureaus, Information Bureaus | |
| AI | 1-21 | Indexes (General) |
| 21 | Indexes to Individual Newspapers | |
| AM | 1-501 | Museums (General), Collectors and Collecting |
| 10-101 | Museography | |
| 111-160 | Museology, Museum Methods, Techniques, etc. | |
| 200-501 | Collectors and Collecting, Private Collections | |
| AN | Newspapers | |
| AP | 1-271 | Periodicals (General) |
| 101-115 | Humorous Periodicals | |
| 200-203 | Juvenile Periodicals | |
| AS | 1-911 | Academies and Learned Societies (General) |
| AY | 10-2001 | Yearbooks, Almanacs, Directories (General) |
| 30-1730 | Almanacs | |
| 2001 | Directories | |
| AZ | 20-999 | History of Scholarship and Learning, The Humanities |
| 999 | Popular Errors, Delusions, and Superstitions |
To the Library of Congress Classification index
