Instructions used to ensure that a font displays properly at small point sizes. When fonts are scaled from a common algorithm, serifs, accents and various lines in small fonts may not line up properly with the pixel grid on screen. Hinting applies rules to specific characters; for example, a hint would ensure that both vertical lines in an H have the same thickness or that the sides of the "v" in the middle of an M are uniformly shaped. See
scalable font and
font smoothing.