When Identifying a basic Rotary Switch, locate the number of poles and throws:
Number of Poles (P) are the number of pole lugs, where the Number of Throws (T) are the number of throw lugs divided by the number of pole lugs.
Above photo has 3 pole lugs and 12 throw lugs, therefore this is a 3-Pole 4-Throw switch (3P4T). CKN11808-ND is an example of a 3P4T switch.
Various Pole and Throw Schematics:
Source
There are also Rotary Switches without a common pole(s), referred to as “Adjacent Contact”. These are missing the center contacts of the switch, and are common in ceiling fans, industrial equipment, and portable tools.
CKN11058-ND is a SP10T Adjacent Contact Model
CKN9483-ND is a DP5T Adjacent Contact Model
Although rare, some rotary switches have special outputs similar to encoders, such as BCD, and BCD Compliment.
450-1885-ND is a BCD Model
450-1884-ND is a BCD Compliment Model
See also:
Switch Basics, Examples of Pole and Throw
I am looking for a rotary switch made by C&K
Why does my rotary switch not have a common pin?
Shorting vs Non Shorting on rotary switches
Switch Circuits and Functions