DE-9 means 9-pin D-SUB series D subminiature connector in Electronics
Similar to DE-9
3D - Three Dimensional 3R3 - 3.3 ohm Resistor 3SR - Three Station Rotating 4P4T - Quad-Pole Quad-Throw 4W - 4-Watt Resistor 4WA - Four Wire Analog 4WAI - 4-Wire Analog Interface