What means
It marks the leftmost cell of a 4×4 block's third row.
Think of a square divided into four rows and four columns. The Robotron Z9001, a home computer made in East Germany, used a fixed character set to place graphic cells like this together and draw simple pictures on its text screen.
Robotron presented the Z9001 publicly in 1984. The machine's own code for this tile was D8 (hexadecimal); Unicode preserves the same cell as a distinct text character for old computer data, emulators, and text-mode graphics.
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
𜺘\1CE98Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.
