Exceptions: The focus indicator is determined by the user agent and cannot be adjusted by the author, or The focus indicator and the indicator's background color are not modified by the author. Note 1 What is perceived as the user interface component or sub-component (to determine enclosure or size) depends on its visual presentation . The visual presentation includes the component's visible content , border, and component-specific background. It does not include shadow and glow effects outside the component's content, background, or border. Note 2 Examples of sub-components that may receive a focus indicator are menu items in an opened drop-down menu, or focusable cells in a grid.