Protecting servo drive outputs from inductive loads.
If I understand correctly, you will be using one of the 5 driver output to drive a relay which will connect/disconnect the enable of the driver.

The function of the relay is irrelevant, a relay is an inductive load, hence you will need to "Use an appropriate external protective circuit or device to reduce the risk of inductive direct current load damage ".
Even if you just drive the relay to make it click, without serving any other purpose, you will need to protect the servo driver output. 

An inductor (the relay coil) can't change it's current instantly, the purpose of the protection circuit is to provide a path for the current when the coil is switched off. Otherwise, a voltage spike will occur possibly damaging the output of the servo driver.