Text figures (also known as non-lining, lowercase, old style,ranging, hanging, medieval, billing, or antique figures or numerals) are numerals typeset with varying heights in a fashion that resembles a typical line of running text, hence the name. They are contrasted with lining figures (also called titling or modern figures), which are the same height as upper-case letters.
In text figures, the shape and positioning of the numerals vary as those of lowercase letters do. In the most common scheme, 0, 1, and 2 are of x-height, having neither ascenders nor descenders; 6 and 8 have ascenders; and 3, 4, 5, 7, and 9 have descenders. Other schemes exist; for example, the types cut by the Didot family of punchcutters and typographers in France between the late 18th and early 19th centuries typically had an ascending 3, a form preserved in some later French typefaces. A few other typefaces used different arrangements. Sometimes the stress of the '0' is made different from a letter 'o' in some way, although many fonts do not do this.
High-quality typesetting generally prefers text figures in body text: they integrate better with lowercase letters and small capitals, unlike runs of lining figures. Lining figures are called for in all-capitals settings (hence the alternative name titling figures), and may work better in tables and spreadsheets. During the period of transition from text figures to lining, a justification for the old system was that the height differences helped distinguish similar numbers, while a justification for lining figures was that they were clearer (being larger) and that on uses such as page numbers they looked better giving all page numbers the same height. Amusingly, as several later writers have noted, the printer Thomas Curson Hansard in his landmark textbook on printing Typographia describes the new fashion as 'preposterous', but the book was printed using lining figures and the modern typefaces he also criticised throughout.