In the Compact Definite Purpose Contactors, what is the difference between Single-Pole and Single-Pole with shunt?

All three sets of the Compact Definite Purpose Contactors are slightly different from each other, though physically they are all the same footprint.

The single pole only has one contact for making and braking a signal, whereas the Two-pole version obviously has 2 power poles that are opened and closed by the coil.

The Single-Pole with Shunt is a Single-pole contactor only, but with termination locations to tie the non-switched leg together.  In other words the top and bottom terminals or the right hand side are electrically the same, but it is not switched or opened and closed via the coil, rather always maintained.  Thus, it gives convenient termination locations for the non-switched leg.