Three-Quarter Block

▛ is a building block for pictures made of text. Imagine one character cell split into four quarters. ▛ paints the upper left, upper right and lower left, and leaves the lower right white. Its name says exactly that, and its three siblings do the same with a different empty corner: ▜ (lower left empty), ▙ (upper right empty) and ▟ (upper left empty). Smaller pieces fill one or two quarters, such as ▘ and ▚.

The idea is older than smartphones. Many home computers of the 1970s and 80s could not draw free pixels in text mode, so they shipped block-graphics characters, often a set of 2×2 quadrants: put the right ones next to each other and you get bar charts, borders, maps and game sprites. (Teletext pages built theirs from a finer 2×3 mosaic.) The half blocks ▀ ▄ ▌ ▐ and the full block █ entered Unicode first, drawn from older character sets including that of early IBM PCs. The ten quadrant pieces, ▛ among them, came in Unicode 3.2 in 2002 after a proposal to let old terminal screens and their emulators be reproduced faithfully. Together with the half blocks, █ and a blank space they cover all 16 ways of filling a 2×2 grid.

How do people actually use ▛ today?

Mostly as a corner. In decorated messages, profile bios, forum signatures and chat art, ▛ starts a heavy frame: ▛▀▀▀▜ across the top, ▙▄▄▄▟ along the bottom, with ▌ and ▐ or █ for the sides. It also serves as a single pixel in larger block drawings, from hearts and logos to tiny game maps, and terminal programs can use the quadrant set to draw charts and images in a text window.

The character carries no meaning of its own. If someone sends you a lone ▛, it is usually a slip, a test of whether your phone shows it, or a piece of a drawing that lost its neighbours. Block art only works when the pieces sit in a grid: in a font where letters have different widths the squares drift apart, and a frame that looked perfect on the sender's screen can arrive crooked.