In typography

Typography

Typography is the art and technique of arranging type in order to make language visible. The arrangement of type involves the selection of typefaces, point size, line length, leading , adjusting the spaces between groups of letters and adjusting the space between pairs of letters...

, an ascender is the portion of a minuscule letter in a Latin-derived alphabet that extends above the mean line

Mean line

In typography, the mean line, also known as midline, is the line that determines where non-ascending lowercase letters terminate in a typeface...

 of a font

Typeface

In typography, a typeface is the artistic representation or interpretation of characters; it is the way the type looks. Each type is designed and there are thousands of different typefaces in existence, with new ones being developed constantly....

. That is, the part of a lower-case letter that is taller than the font's x-height

X-height

In typography, the x-height or corpus size refers to the distance between the baseline and the mean line in a typeface. Typically, this is the height of the letter x in the font , as well as the u, v, w, and z...

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Ascenders, together with descenders, increase the recognizability of words. For this reason, British road signs no longer use all capital letters.

Studies made at the start of the construction of the British motorway network concluded that mixed-case letters were much easier to read than "all-caps" and a special font was designed for motorway signs. These then became universal across the U.K. See Road signs in the United Kingdom

Road signs in the United Kingdom

Road signs in the United Kingdom conform broadly to European norms, though a number of signs are unique to Britain and direction signs omit European route numbers.-History:...

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