Copper Sleeve over IEC

Ozzy, I suspect there is a resistor in terminal and digital shorting plugs or that they are merely covers, such as those by Cardas.

There is a resistor.

"A 75 Ohm resistor within an RCA phono plug for the termination of the unused digital output or input can avoid this problem. The result is a more accurate, cleaner and well-balanced sound."

I wish they had chosen another name rather than shorting plug. People are going to put real shorting plugs into output and damaging their electronics.

They should call it a "Loading plug" opposed to "Shorting Plug"

Actually, I think they call it a terminator. I have been calling it a shorting plug, sorry.