Posts depicting a tangibly visible user interface, that is, a visual layout of various elements that a user might need in order to interact with software or some other technological product. Often features buttons, overlaid text, and/or a list or menu of choices. Older or more technically-oriented user interfaces may instead consist purely of text on a solid color background.
Most game screenshots or spoofs of the same (fake screenshots inspired by games) will likely qualify for this tag.
Avoid using this tag for physical input devices or other mechanical elements if there is no visible "UI screen", even if they might technically qualify as user interfaces (e.g. HID) in a formal sense.