Dropdown Menus should always be positioned over their emitting elements such that the currently selected menu item appears on top of the emitting element.
Can be used on a wide variety of emitting elements (icon, button, image, input etc.) and display a list of options, each on one line.
Generally only used in action toolbars, where the number of options a user could interact with is problematic with regard to having enough space.
Aside from customised highlight & scroll, fairly standard material design select menu.
Used mostly for inline dropdowns inside forms. While specific width is not very important or strict, only 1 or 2 such custom widths should be used in any 1 such forms.
