An "overline" is a typographical feature that consists of a horizontal line placed above a character or a group of characters. It is often used in mathematics and phonetics to indicate specific functions, such as denoting a repeating decimal or representing a long vowel sound. The overline can also serve to highlight or emphasize certain text in various contexts. In addition to its use in writing, the overline appears in various fields, including computer science and graphic design. In programming, it may be used in markup languages to create visual effects, while in design, it can enhance the aesthetic appeal of text in logos or advertisements.