实心竖矩形 ▮

This symbol is used in geometry, geographic map legends, design, art, textual graphics, riddles, and rebuses.

The black vertical rectangle is one of the variations of the ∎ symbols in typography. This symbol is sometimes placed at the end of a proof to signify 「Q.E.D.」 or 「quod erat demonstrandum,」 which means 「that which was to be demonstrated.」

You may come across a symbol similar to 25AE in geographic map legends, but with a top pointed end. This symbol is used to represent graphite deposits. Diamonds and pencil cores are made from this material.

The rectangle is one of the basic symbols in geometry, which explains its prevalence not only in this field of study but also in design.

The black vertical rectangle is used in textual graphics to decorate web pages, user nicknames on social media, and messaging platforms.

As for riddles and rebuses, this symbol can indicate that a certain object or phenomenon is black.

符号 「实心竖矩形」 包含在 「几何图形」 块的 「幾何形狀」 子块中，并在1993年作为Unicode版本1.1的一部分获得批准。