What means
It fills one cell in a low-resolution screen drawing.
On Kaypro personal computers, each graphics cell was a 2 × 4 pixel grid. A May 1983 Kaypro manual explains how programs switched to graphics output and set the little lit or unlit areas. A 2022 Unicode proposal maps this pattern to the Kaypro reverse octant entry, code DD.
“Octant” means the cell is split into eight parts; the digits identify which pattern this tile shows. Kaypro used these tiles to build rough drawings on a character-cell screen, and Unicode carries the pattern forward as a text character.
Does “reverse” mean mirrored?
No. Kaypro’s inverse-video mode reversed light and dark.
A 1984 Kaypro hardware description says inverse video switched which pixels lit up; it did not move their positions within the 2 × 4 grid.
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
𜵅\1CD45Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.