Wounded in action
From Halopedia, the Halo wiki
Wounded in Action, WIA, is a classification used by the United Nations Space Command for troops on the battlefield or in a report. It is used when a soldier receives wounds in battle.
When Spartans became missing or were killed they were classified as Missing In Action (MIA) or Wounded in Action (WIA) to give to give the illusion that Spartans never die. It also gave the troops more morale. While it is extremely likely that all Spartans have been wounded in action, <ref>Halo: First Strike.
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