Used to indicate how well a font can represent a particular Unicode character point for a particular script.
The character is not representable with the font.
The character is represented in a way that may be comprehensible but is not the correct graphical form. For instance, a Hangul character represented as a a sequence of Jamos, or a Latin transliteration of a Cyrillic word.
The character is represented as basically the correct graphical form, but with a stylistic variant inappropriate for the current script.
The character is represented as the correct graphical form.