removing icons

i have seen it from other map and wonder how it works?
in some games the attack icon or petrol icon had been remove and this allows the hero to master more spells. Can someone teach me now it is done?

Just like removing the rally point ability, you could use a custom script, and the Unit - Remove ability function.

Lets see. Rally point is ARal, so I would think patrol would be APat, and attack AAtt.

Make the trigger with any ability, and custom text it. Then change that field. Let me know, because I am curious too.