Double-Line T Junction

It marks where a double horizontal rule splits downward. At a table's top edge, its two vertical strokes begin column dividers; the character reads as part of a larger border.

Box-drawing characters were made for character-cell screens: grids of fixed-width text positions used to draw borders, forms, and menus. The family descends from graphics in vendor and national standards used before 1990, including IBM PC graphics, China's GB 2312 and Korea's KS X 1001 character sets, and terminal sets. Videotex, an early screen-information service delivered over telephone lines, used a light-versus-heavy line distinction by November 1988.

These marks let computers draw menus, forms, and borders on fixed-width screens without bitmap graphics. One present-day example: as of 2026, Obsidian's community plugins include a tool that converts pasted terminal tables into Markdown, a plain-text formatting style for documents.