Military moustache
A moustache worn under army rules, which have both required and forbidden facial hair at different times.
Also: regulation moustache
Armies have long regulated faces. The British Army required soldiers to wear a moustache from the 1860s until 1916, when the order was dropped. Many armies now ban beards for most soldiers, partly so gas masks seal, while allowing neat moustaches. The Indian Army permits Sikh soldiers to keep unshorn beards and turbans as part of their faith. Air force moustaches in the RAF gave rise to large handlebar styles in the Second World War.