| T | Technology |
| T10 | to | T995 | General Technology |
| TA164 | to | TA1280 | General Engineering |
| TC160 | to | TC1645 | Hydraulic Engineering |
| TD159 | to | TD949 | Environmental Technology & Sanitary Engineering |
| TF200 | to | TF1126 | Railroad & OperationEngineering |
| TH845 | to | TH9745 | Building Construction |
| TJ170 | to | TJ1496 | Mechnical Engineering & Construction |
| TK301 | to | TK9971 | Electrical Engineering |
| TL500 | to | TL4050 | Aeronautics, Astronautics |
| TN263 | to | TN271 | Mineral Deposits, Prospecting |
| TN275 | to | TN325 | Practical Mining Operations |
| TN331 | to | TN347 | Mine Transportation, Machinery |
| TN400 | to | TN580 | Ore Deposits |
| TN600 | to | TN799 | Metallurgy |
| TN799.5 | to | TN948 | Nonmetallic Minerals |
| TN950 | to | TN997 | Building & Ornamental Stones |
| TP155 | to | TP1185 | Chemical Technology |
| TR250 | to | TR1045 | Photography |
| TS155 | to | TS2283 | Manufactures |
| U | Military Science |
| UA985 | to | UA997 | Military Geography |
| UC | | | Military Transportation & Maintenance |
| UF | | | Artillery and Tactics |
| V | Naval Science |
| VK588 | to | VK597 | Marine Hydrography, Hydrographic Surveys |
| VK600 | to | VK794 | Tides and Currents |
| VK798 | to | VK997 | Pilot Guides, Sailing Directions |
| VK1250 | to | VK1299 | Shipwrecks |
| VM | to | | Naval Architecture, Marine Engineering |
| Z | Bibliography, Library Science |