| Acronym | Meaning |
| LH | Left Hand |
| DCT | Damage Control Tpnr (trident-21c11) |
| NAVCIPS | Navy Standard Civilian Pay System |
| PDES | Product Data Evolvement System |
| PVS | Periscope View Simulators (associated With 21a Series) |
| HP | Horse Power |
| CVG POS | Compressor Variable Geometry Position |
| LBL | Left Butt Line |
| ELOS | Single Channel Anti-jam |
| MUTE | Multiplex Unit For Transmission Elimination |