Network cable tester (Circuit and design ideas, February 1997): There is
room for confusion in regards to the wiring of the shorting socket shown in
the circuit diagram. While the pin numbers for the socket weren't shown,
people unfamiliar with the pairing of cables in RJ45 plugs might be led to
believe that the socket is to be wired with pins 1 and 2 shorted, pins 3 and
4 shorted, etc...  
The correct wiring for the shorting socket is shown below, but note that the
actual placement of the pairs is dependent on the plug's orientation -- see
AS 3080 for the standard connection.
(Our thanks to reader Bob Lions for pointing this out to us.)