A military artillery observer or spotter is responsible for directing artillery and mortar fire, mostly at opportunity targets, and may be a Forward Air Controller (FAC) for close air support and spotter for naval gunfire support. Most commonly observers accompany a tank or infantry manouvre unit. More recently a mission controller for an Army Unmanned Air System (UAS) may also act as an artillery observer and some armies use special artillery patrols behind the enemy's forward elements.

The terms foobar /ˈfʊːbɑːr/, fubar, or foo, bar, baz and qux (alternatively quux) are sometimes used as placeholder names (also referred to as metasyntactic variables) in computer programming or computer-related documentation. They have been used to name entities such as variables, functions, and commands whose purpose is unimportant and serve only to demonstrate a concept. The words themselves have no meaning in this usage. Foobar is sometimes used alone; foo, bar, and baz are sometimes used in that order, when multiple entities are needed.