Are they the same or does the NONE imply a middle stop position where no connections are made ?
It is indeed a 3 possible position switch. Some on-none-on switches can be had with a momentary spring return on either on or just one of the on positions.
Are you saying that the Carling description is wrong ?
I guess I could be wrong according to Carling (which I've never heard of). I just never heard of a simple on/off switch referred to as on/none/off. I guess the problem is that a given switch has both an electrical description (spst,spdt,dpdt,etc) and a mechanical description (toggle, momentary, center off, etc.
After a few misordered switches in the 70s I alway try and find a datasheet for any specific switch and if not available then pass on it. Pots can be just as error prone to order for all the various types (taper, gangs, detented, etc) Some stereo volume/balance pots from the 70s can be near impossible to source anymore.