How to do it: You select a unit(s), put a move command on minimap followed by a shift-Patrol command on the same spot.
What happens: The unit(s) move(s) to the location and then puts a patrol command from point A to point A, i.e static patrol.
What traits ive found:
1. It becomes passive-aggressive, i.e its always passive (except turret units (tank/gol)) until someone fires at it or its surroundings (allied building or unit) then it retaliates.
2. It retaliates and follows the enemy, after that unit is dead it changes target to whatever is in the surrounding area of its acquisition range. (not tested if it attacks targets on its way back, im assuming so)
3. After killing all units in the area it returns to the static patrol position and repeats the behaviour, i.e not caring about anything except if fired upon or the surroundings.
4. Ive found Lurker attack breaks this behaviour where it just 'stops' after returning to patrol position.
Useful scenarios?
Well ive been testing it with Protoss wall to negate scarab lures (wasted shots from faking an attack). When enemy for example actually attacks the wall the Reaver starts shooting at whoever is attacking the building.
As mentioned in the "1 medic per base vs storm drops" you can use this on a Medic for it to be static but still walk to heal, then return to position out of storm area.
When it comes to Goliaths they tend to walk away attacking targets once you upgraded the 'Charon Booster' as that extends its acquisition range from the normal 6 (Ground Attack Range which also is the acquisition range for Gols)
This could be used on Goliaths for still attacking targets but not chase their targets until they are actually shot at. People tend to lure Gols because they are indeed stupid once you upgraded Charon Boosters. This would force the enemy to actually attack before the chase happens.
Further testing to be done, maybe not that useful finding but still hilarious behaviour. Maybe @Tec27 could tell us why this behaviour happens as he knows something about the code
Replay: https://ufile.io/gttxsobh
Replay2: https://ufile.io/vfdtpl9r
Watch the replays in single player mode, as i use cheats to get money the replay bugs out in multiplayer