This can also be used for attaching the camera to various brackets or adapters. Both notations may overlap with other uses of parentheses and brackets in mathematics. The tool for installing and removing these bottom brackets is often also a spline. Durable frames with low bottom brackets and short chainstays improve maneuverability. The round brackets indicate optional constituents. Other features include applied decorative eave brackets, quoins and cornices. Standard orthography is added in angled brackets. The teeth move when the arch wire puts pressure on the brackets and teeth. They fit only frames with American sized (also known as "Pro size") bottom brackets. COBOL's syntax is usually described with a unique metalanguage using braces, brackets, bars and underlining. The frame brackets it as outside of normal discourse. The brackets and the dash are also often omitted. Ada visually emphasizes label definitions using angle brackets. Some just provide points for wins by correctly picked teams in the brackets. Square brackets ("[" and "]") are used to indicate that a value is "optional".