What ║ means
Use it to divide columns or draw a frame's vertical edge. In command-line output or a code comment, it can mark the edge of a text diagram.
The box-drawing family grew from multiple national, vendor, and terminal standards in use before 1990, including IBM PC graphics and Videotex, a service for displaying information on terminals. A November, 1988 Videotex recommendation distinguished light and heavy line weights.
A double-rule frame stays continuous only when adjoining pieces have matching line weights.
Technical or diagrammatic in layouts; decorative when drawn on its own.
What it means when someone sends it to you
2 readingsDon'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 ║
║\2551Codes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.

