The Holnists, from the 1998 Us movie The Postman, are a group of violent survivalists who appear to eschew most forms of technology beside that used to wage war. They follow a philosophy set down by their founder Nathan Holn, hence their name.
Although strictly speaking the Holnists do wear a uniform, the bichromatic mixture of orange and black in their clothes, the use of "8" in armbands and other decorations (Holn having set down 8 laws as part of his philosophy) and the fairly common use of visor caps gives them a feeling of rough uniformity.
They appear to wear insignias inspired by or identical to contemporary US ones as "general" bethlehem wear stars on his collar and hat and a man is observed with upward pointing chevrons on his upper arms like a sergeant. Other characters are identified by ranks, colonel and captain, any insignias, if present, are not visible.