Secret flasks come in the form of cell phones, smart phones, digital cameras, binoculars, lipstick cases, sunscreen tubes, water bottles with caps that look unopened, shampoo, conditioner and lotion bottles, plastic pouches strapped to the gut like fake beer bellies, fake bras, fake underpants and fake tampons, to name a few. The success of any secret flask depends on how realistic it looks or how easy it is to conceal.
Flasks have been around since ancient times in the form of animal skins or bladders used to carry liquids long distances. Flasks began to be used in the United States in the 1800s in the form of canteens, and secret flasks gained popularity in the United States during prohibition. The term "bootlegger" was coined when secret flasks began to be hidden in trouser legs or boots. As of 2014, flasks are used where alcohol is not allowed, in instances where the flask holder would rather bring her own alcohol than pay more for what is available for sale or in any situation where drinking should be concealed. Despite the plethora of secret flasks available, some believe etiquette demands that the flask only be carried in the trouser hip pocket, jacket pocket or boot.