[Sgt_Walrus]

Hi Smersh
It is pretty simple bro.
It is a function to stop your units retreating off the map in a set direction...which is often straight toward the enemy if you are playing a stock scenario where the designer has made the battle N-S rather then W-E.

IIRC you click on the unit (or formation?) and then set a "rally" point for that unit. When they retreat, they will retreat to that hex you have chosen.

try it out, and as always, read the game guide!

Cheers
SGT