DayZ field wiki · Start
Combine and split
Stacks are a choice
Short answer
Ammo, rags, and food stack until they don't. Combining is a click. Splitting is how you share with the duo.
Also: split stack · combine items
How it works
A stack is not a second item until you split it. The duo who never splits rags is the duo who bleeds together.
What to do
Split before the fight. Combine after the well. Don't sort stacks in a doorway.
Don't
Don't dump a whole ammo pile on the floor as a bit.