What ⺄ means
It marks the 乙 radical in character indexes.
A radical is a filing label. The Kangxi Dictionary grouped characters by radical and leftover strokes; it was completed in 1716. ⺄ is the chart form for its fifth heading.
乙 appears in oracle-bone writing (questions carved on bones or shells for divination), bronze inscriptions, Chu manuscripts from an ancient Chinese state, and seal script, an old formal style. Oracle-bone inscriptions date to 14th–11th-century BCE China. 乙 is the second sign in a traditional ten-sign calendar cycle and can mean “second.”
Indexes vary: Taiwan’s education ministry lists 乙 under radical 5 (2024); a mainland Chinese common-character list files it under 乛 (2019).
Don't confuse it with
1Questions people ask
1Why does ⺄ 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 ⺄
⺄\2E84Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.