Hello,
This Switch is a DPDT style switch. The illustration is to show how to use it as a SP3T switch. This is set up to be a ON-ON-ON style SP3T.
The jumper wire is put in there to connect the two poles together. Without the jumper it would be a DPDT switch.
There are other circuit styles for the DPDT switch depending on what is required.
Yes it could be different for a ON-OFF-ON DPDT style switch. The best thing is to look at the switch and check out the wiring diagram for it.
That will give the best description on how to correctly wire the switch.
I hope this will help
Any questions Please let me know.
Paul.