First of all, please bear with my ignorance, as I'm not really good at electronics. I've come across rotary switches/potentiometers with a lug as circled in the picture. What is the use of this lug? Is is for poisitoning/orientation?
Then, there are 14 terminals on the rear of the switch (as shown in the picture below)
and I do not have a clue as to their designation, i.e. which is terminal #1, which is #12, and which is #A/#C (the arrowed numbers are my guess only) when referring to the connection diagram shown below
Thanks very much for your help.