This character is a Other Symbol and is commonly used, that is, in no specific script.
The glyph is not a composition. Its East Asian Width is wide. In bidirectional text it acts as Other Neutral. When changing direction it is not mirrored. The word that U+2B1B forms with similar adjacent characters prevents a line break inside it.
The CLDR project calls this character “duży czarny kwadrat” for use in screen reading software. It assigns these additional labels, e.g. for search in emoji pickers: czarny, duży, figura geometryczna, kwadrat, średni.
This character is designated as an emoji. It will be rendered as colorful emoji on conforming platforms. To reduce it to a monochrome character, you can combine it with Glyph for U+FE0EVariation Selector-15: ⬛︎ See the Emojipedia for more details on this character’s emoji properties.
Wikipedia ma następujące informacje na temat tej współrzędnej kodowej:
In Euclidean geometry, a square is a regular quadrilateral, which means that it has four sides of equal length and four equal angles (90-degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length adjacent sides. It is the only regular polygon whose internal angle, central angle, and external angle are all equal (90°), and whose diagonals are all equal in length. A square with vertices ABCD would be denoted ABCD.