Horizontal One-Eighth Block 2

A horizontal line in the second of eight rows of a character cell. Imagine the space one letter takes up, sliced into eight horizontal strips. A black strip in the top row is ▔, in the bottom row ▁; both have been in Unicode since its early days. The six in between, rows 2 to 7, were missing until 2020, when they were added as 🭶 🭷 🭸 🭹 🭺 🭻. The "-2" in this character's name is simply its row number, counted from the top.

Together the eight let a line sit at any height inside the text, which is what you need to draw with characters alone: a ruled line under a title, the edge of a box, the floor a little figure walks on, or the bars of a chart. A matching set 🭰 🭱 🭲 🭳 🭴 🭵 does the same for vertical lines, counted from the left.

Where does 🭶 come from, and who uses it now?

Commodore home computers; today it serves text art and retro emulators. The Commodore PET of the late 1970s, and later the VIC-20 and Commodore 64, showed text in a fixed grid of cells and had no cheap way to draw single pixels in that mode. Instead their character set, PETSCII (Commodore's own version of the ASCII code table), included dozens of little graphic tiles: corners, diagonals, checkerboards and horizontal lines at every height. Programmers and hobbyists assembled pictures, frames, menus and even simple games by placing tiles in the grid, and the thin line at each row was a basic building brick.

This particular line was one of them: on a PET, VIC-20 or C64 in graphics mode, pressing Shift+E put it on screen. The keypress sent PETSCII code $C5, and the machine stored the tile in screen memory as screen code $45, the number that picks a shape from the character set. When Unicode added the Symbols for Legacy Computing block in version 13.0 (2020), it encoded these old tiles so that screens and listings from such machines could be converted to ordinary text with their line drawings intact. That is why 🭶 exists as a text character today, and why you meet it in retro-computing screens turned into text, terminal and text art, and text-mode interfaces that want a hairline at a precise height.