Among other things, it directed the troops about the treatment of prisoners, and gave commanders of units wide powers to carry out executions at their sole discretion.
The army favored a declaration of war, in order to treat the prisoners as civilians, wherein execution for treason would become legal.
A compromise was reached: the motivation was that an extrajudicial execution of a "saboteur caught red-handed" or "quarter at discretion" was a justifiable homicide committed in defense of life or property.
In practice, battlefield commanders decided which Red prisoners would be released, detained or considered dangerous and summarily executed.
Due to this policy, it can be difficult to distinguish whether deaths "in battle" actually occurred in combat or as summary executions after the fact.