How did Erik save Hans life in the First World War

The day their platoon was to go into battle, the Sergeant asked which one of the men had good handwriting. No one volunteered. The Sergeant then added that whichever man had good handwriting wouldn't be going into battle, yet none of the men wanted to seem like a coward, so Erik nominated Hans. Hans was then appointed to write letters for the captain. The rest of the men were all killed.