Since italic styles clearly look different from regular (roman) styles, it is possible to have 'upright italic' designs that have a cursive style but remain upright. In Latin-script countries, upright italics are rare but are sometimes used in mathematics or in complex texts where a section of text already in italics needs a 'double italic' style to add emphasis to it. Donald Knuth's Computer Modern has an alternate upright italic as an alternative to its standard italic, since its intended use is mathematical typesetting.