| idth="50" rowspan="28"| | width="30"|A | GENERAL WORKS |
| ||PHILOSOPHY. PSYCHOLOGY. RELIGION |
| ||AUXILIARY SCIENCES OF HISTORY |
| ||HISTORY: GENERAL AND OLD WORLD |
| ||HISTORY: AMERICA |
| olspan="2"| {| cellspacing="0" cellpadding="0" |
| idth="50" rowspan="3"| | colspan="2"|This class is not broken down into letter sub-classes. |
| idth="100"|11-143 | width="400"|America |
| 51-889 | United States | } |
| ||HISTORY: AMERICA |
| olspan="2"| {| cellspacing="0" cellpadding="0" |
| idth="50" rowspan="6"| | colspan="2"|This class is not broken down into letter sub-classes. |
| idth="100"|1-975 | width="400"|United States local history |
| 001-1145.2 | British America (including Canada) |
| |Dutch America |
| 170 | French America |
| 201-3799 | Latin America, Spanish America and History of Brazil. | } |
| ||GEOGRAPHY. ANTHROPOLOGY. RECREATION |
| ||SOCIAL SCIENCES |
| ||POLITICAL SCIENCE |
| ||LAW |
| ||EDUCATION |
| ||MUSIC AND BOOKS ON MUSIC |
| ||FINE ARTS |
| ||LANGUAGE AND LITERATURE |
| ||SCIENCE |
| ||MEDICINE |
| ||AGRICULTURE |
| ||TECHNOLOGY |
| ||MILITARY SCIENCE |
| ||NAVAL SCIENCE |
| ||BIBLIOGRAPHY. LIBRARY SCIENCE. INFORMATION RESOURCES (GENERAL) |
Letter classes I, O, W, X and Y are not standardly used.