The manicule, or pointing hand, was thought to have originated in scribal traditions of the medieval and Renaissance periods, where it often featured in the margins of manuscripts to indicate amendments or notes. The illustrated hands varied during the 14th and 15th centuries, ranging from the the very artistic with elaborately drawn cuffs and shading, to the barest of squiggly strokes.
In modern usage, the manicule (also known as an ‘index’) is used to draw attention to specific areas of a text, such as noteworthy passages or inserts. Some encyclopaedias use them to cross-reference articles and they sometimes feature on magazine pages to indicate that a story or article continues overleaf. American writer Kurt Vonnegut made extensive use of the symbol at the beginning of each new paragraph in his 1973 novel Breakfast of Champions, and Gravity’s Rainbow writer Thomas Pynchon, who was preceded some 600 years by this rather spidery rendition drawn by a 14th century scribe, parodied it by depicting a middle finger, rather than the index, pointing to the text.
Berkeley, Bancroft Library, BANC MS UCB 085 (14th century) via Medieval Books