[Elecraft] If it plugs in it should work

[alan]

There is no doubt there are many fields where being able to plug something wrongly is life threatening or way too expensive an outcome. But, there are many more electrical/electronic systems than different plugs and sockets.  It is simply not realistic to achieve although a connector with several key-way options can give 2^n different fits.  Edge fit PCB connectors used that method.Witness the number of different mike plug options even for mating plugs.  The two pole version used by Kenwood and Yaesu some 20 years ago were different polarity.  Realistically we are forced back to colour if possible (PS2 mouse & keyboard) and good labels.  As soon as third party kit is introduced then all bets are off.73  Alan  G0HIQ