| Separate Fire Mains | | Naval Support | |
| Shared Instructors | | Special Forces Doctrine | |
| Shell Dyes | | Naval Support | |
| Ship Hull Super Heavy | | | 1936 |
| Shock-Hardening Techniques | | Artillery | 1941 |
| Shore Parties | | Special Forces Doctrine | |
| Signal Company I | | Support Companies | 1936 |
| Signal Company II | | Support Companies | 1939 |
| Signal Company III | | Support Companies | 1942 |
| Signal Company IV | | Support Companies | 1945 |
| Small-Caliber Armor Piercing Shell | | Naval Support | 1942 |
| Small-Caliber Semi-Armor Piercing Shell | | Naval Support | 1936 |
| Smoke Generators | | Naval | 1922 |
| Sp Improved Repair Ship | | Naval Support | 1942 |
| Sp Improved Support Ship | | Naval Support | 1942 |
| Sp Land Large Caliber Kinetic Energy Sabot Gd Tech | | | 1936 |
| Sp Land Large Caliber Kinetic Energy Sabot No Gd Tech | | | 1936 |
| Sp Naval Proximity Fuze Tech | | | 1940 |
| Sp Naval Repair Ships Pick A | | | 1940 |
| Sp Naval Repair Ships Pick B | | | 1940 |
| Sp Naval Repair Ships Pick C | | | 1940 |
| Sp Naval Support Ships Pick A | | | 1940 |
| Sp Naval Support Ships Pick B | | | 1940 |
| Sp Naval Support Ships Pick C | | | 1940 |
| Sp Naval Underway Replenishment Pick A | | | 1940 |
| Sp Naval Underway Replenishment Pick B | | | 1940 |
| Sp Rockets Improved Rocket Bomber | | Engineering | 1945 |
| Sp Rockets Rocket Bomber | | Engineering | 1944 |
| Special Forces | | Infantry | 1938 |
| Specialized Field Manuals | | | 1943 |
| Standardized Tenshioned Replenishment Alongside Method | | | 1943 |
| Strategic Air Lift Corps | | Special Forces Doctrine | |
| Strategic Airlifter | | Air | 1948 |
| Strategic Bomber1 | | Air | 1936 |
| Strategic Bomber2 | | Air | 1940 |
| Strategic Bomber3 | | Air | 1944 |
| Streamlined Line | | Industry | 1943 |
| Stronghold Network Tech | | | 1936 |
| Sturmtruppe Battalion Tech | | | 1936 |
| Suicide Charge | | | 1944 |
| Super Heavy Art | | | 1943 |
| Super Heavy Spaa | | | 1943 |
| Super Heavy Tank | | Armor | 1941 |
| Super Heavy Td | | | 1943 |
| Super-Heavy Armor Piercing Shell | | Naval Support | 1942 |
| Super-Heavy Battleship II | | Naval | 1944 |
| Super-Heavy Tank | | Armor | 1941 |
| Supersonic Fighter | | | 1950 |
| Supersonic Small Airframe | | | 1950 |
| Support Equipment | | Support Companies | 1918 |
