.... and a shorted turn is on the bad list.
for the same reason, you never mount a toroid transformer to a chassis where the center bolt makes electrical contact on both ends to ground....
for some strange reason the Marconi spark gap transmitters (an adaptation of the Tesla coil) used shorting strips on the tap switches of the tuning inductors.... and somehow it still worked (although there must have been huge amounts of energy lost in the shorting strips). maybe this partially explains why the common theory was that shorter wavelengths than 200M (1.5Mhz) were considered to be useless for long range communication, the shorter the wavelength in those transmitters (and receivers, which used the same tuning techniques), the more taps connected to the shorting pole on the switch (wasting that much more energy).
it's interesting to note (but i've never heard of it being enforced) that "B" type emissions ("damped" spark gap generated RF) are forbidden by the FCC.