| Subclass Q | Science (General) |
| Subclass QA | Mathematics |
| Subclass QB | Astronomy |
| Subclass QC | Physics |
| Subclass QD | Chemistry |
| Subclass QE | Geology |
| Subclass QH | Natural history - Biology |
| Subclass QK | Botany |
| Subclass QL | Zoology |
| Subclass QM | Human anatomy |
| Subclass QP | Physiology |
| Subclass QR | Microbiology |
https://www.loc.gov/aba/cataloging/classification/lcco/lcco_q.pdf