What ↶ means
It marks an anticlockwise turn along an open curve. In a formula or diagram, surrounding marks tell you whether it shows a turn back or connects items along a curved path.
In a set of mathematical markup names called ISOAMSA, cularr and curvearrowleft both identify this character. LaTeX uses \curvearrowleft for the same symbol. These names identify the arrow; its role still comes from the surrounding notation.
Technical and context-dependent; it fits formulas and diagrams more readily than a fixed conversational signal.
Treat it as an undo arrow only when nearby text or the interface defines that reading.
Don't confuse it with
1Questions people ask
1Why does ↶ show as a box on some devices?
Because that device's fonts have no glyph for it. The character is still correct and still copies correctly — the box is a missing glyph, not a broken character.
How to type ↶
↶\21B6Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.