Editing Diode (section)

====Pro Electron====
The European [[Pro Electron]] coding system for active components was introduced in 1966 and comprises two letters followed by the part code. The first letter represents the semiconductor material used for the component (A = germanium and B = silicon) and the second letter represents the general function of the part (for diodes, A = low-power/signal, B = variable capacitance, X = multiplier, Y = rectifier and Z = voltage reference); for example:
* AA-series germanium low-power/signal diodes (e.g., AA119)
* BA-series silicon low-power/signal diodes (e.g., BAT18 silicon RF switching diode)
* BY-series silicon rectifier diodes (e.g., BY127 1250V, 1A rectifier diode)
* BZ-series silicon Zener diodes (e.g., BZY88C4V7 4.7V Zener diode)

Other common numbering/coding systems (generally manufacturer-driven) include:
* GD-series germanium diodes (e.g., GD9){{spaced ndash}}this is a very old coding system
* OA-series germanium diodes (e.g., OA47){{spaced ndash}}a [[Mullard–Philips tube designation|coding sequence]] developed by [[Mullard]], a UK company