| 0-D | Zero Dimensional | |
| 24W | 24 Watts | |
| 2708-0684 | Electronic journal of university of aden for basic and applied sciences | |
| 2M | Micro Miniature | |
| 2M | Micro-Miniature | |
| 2MRPTR | Two Meter Repeater | |
| 2W | Two Wire | |
| 3D | Three Dimensional | |
| 3G | Third Generation | |
| 3Gp | Third generation Partnership Project | |
| 3R3 | 3.3 ohm Resistor | |
| 3SR | Three Station Rotating | |
| 4K | 4,000 pixels | |
| 4K | Four times the number of pixels on a 1080p display (UHDTV) | |
| 4P4T | Quad-Pole Quad-Throw | |
| 4W | 4-Watt Resistor | |
| 4WA | Four Wire Analog | |
| 4WAI | 4-Wire Analog Interface | |
| 4WH | Four Watt-Hour capacity | |
| 4WJ | Four-Way Junction | |
| 4WM | Four Wave Mixing | |
| 7KS | Seven Kilosycles | |
| A | Ampere | |
| A | Anode | |
| A | form A (normally open) contacts | |
