High Quality Content by WIKIPEDIA articles! In typography, all caps (short for "all capitals" or "all capitalized") refers to text or a font in which all letters are capital letters. All caps is usually used for emphasis. It is commonly seen in the titles on book covers, in advertisements and in newspaper headlines. Short strings of words in capital letters appear bolder and "louder" than mixed case, and this is sometimes referred to as "shouting". All caps can also be used to indicate that a given word is an acronym.