Learn English – What do you call the phenomenon where a rectangle □ is shown because a font lacks a glyph

computingprogrammingterminologytypography

Is there a name to describe the situation where a particular character is shown on a computer screen in a particular font, but this font does not have a glyph for this particular character?

Usually, the result looks like this: □

A kind of empty rectangle. Sometimes it shows the code for that character within the rectangle.

tofubake

What do yo call this phenomenon?

If there is no name, is there a common term referring to this "rectangle"?

Some Japanese people call this "tofubake" because rectangles look like tofu.

(It is not mojibake. Mojibake happens when character encoding meta-information is lost. It is not the problem here. Using a better font solves this phenomenon, but does not solve mojibake. Selecting a character encoding solves mojibake, but does not solve this phenomenon.)

Best Answer

The Unicode standard calls it a replacement glyph.