What means
It is one pattern in a two-column, four-row block grid.
The digits 2, 5, 7, and 8 identify its filled cells. On Kaypro CP/M computers in the 1980s, neighboring octants served as semigraphics: software arranged them to sketch low-resolution pictures in ordinary text files. Unicode retains the patterns so software can exchange old text and display it in an emulator, a program that imitates the old machine.
Why use octants for terminal graphics?
They form an even grid without gaps between tiles.
Braille characters use separated dots, while octants fill solid rectangular cells, so adjacent tiles can make a continuous terminal mosaic. Terminal color codes can give the filled and unfilled parts contrasting colors. Cascadia Code added glyphs for all 256 octants on April 30, 2024; the selected font still needs to include this character.
A technical graphics tile whose reading comes from the larger mosaic.
If it renders as a missing-glyph box, check font coverage before treating it as an empty tile.
Don't confuse it with
4Questions 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
𜶽\1CDBDCodes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.