U+21F3 "⇳" Up down White Arrow Unicode Character

U+21F3 "⇳" Up down White Arrow is a typographical symbol depicting a bidirectional vertical arrow with hollow or white arrowheads, pointing both upward and downward. It is officially classified as an arrow in the Unicode standard and is often used in digital interfaces, documentation, and diagrams to indicate the ability to scroll, expand, or navigate in both vertical directions, or to represent a toggle between two states. Its design distinguishes it from its filled counterpart by having an outlined appearance, which can be preferable in contexts requiring a lighter visual footprint or specific aesthetic compatibility.