Actors that can be hurt, coupled with this flag, are capable of taking damage from slime/hellslime/super hellslime sectors just like the player is if they don't have the ironfeet powerup.
I know, it's possible to modify existing maps to have monsters hurt from SectorDamage, but I wanted to make it a bit easier than having to open up the maps and creating ACS scripts for every one of them/giving sector tags...
