Side cap

A side cap is a military cap that can be folded flat when not being worn. It is also known as a garrison cap or flight cap in the United States, wedge cap in Canada, or field service cap in the United Kingdom; or in vulgar slang as a cunt cap. In form the side cap is comparable to the glengarry, a folding version of the Scottish military bonnet. It has been associated with various military forces since the middle of the 19th century, as well as various civilian organizations.