Nope, they don't even need the armband: (6) Inhabitants of a non-occupied territory, who on the approach of the enemy spontaneously take up arms to resist the

Nope, they don't even need the armband: (6) Inhabitants of a non-occupied territory, who on the approach of the enemy spontaneously take up arms to resist the invading forces, without having had time to form themselves into regular armed units, provided they carry arms openly and respect the laws and customs of war.