Marking helpless enemies to claim kill credit, worth up to 300 points across all stats — and refused by Carl.
Facing the surrendered enemy mercenaries filling Larracos, Carl noted he could mark them the way Li Na had, killing them all and raising his stats 300 points across the board just as she had.
He knew a lot of the people following his progress would be enraged that he didn't. They would call him stupid, be disappointed in the lack of blood he shed, and angrily unfollow his feed because he wasn't the monster they hoped he would be. He told them all to fuck off. One look at Li Na was enough to convince him the slope of that path was too steep, and that survival has more than one meaning.
The stat-farming exploit Carl deliberately declines at the end of the war.