In his new book, “Shady Characters: The Secret Life of Punctuation, Symbols & Other Typographical Marks,” Keith Houston reveals the stories behind esoteric punctuation marks, from the pilcrow (¶) to the manicule (☞) to the octothorpe, a.k.a. the hashtag. Many of these have their roots in ancient Greece or Rome, and have evolved over time in Medieval religious texts, Renaissance scholarship, and modern printed works (not to mention the Internet). Here, Houston, who lives in Scotland and also runs a Shady Characters blog, tells the origin stories of some of these marks.

Octothorpe (#)

The story of the hashtag begins sometime around the fourteenth century, with the introduction of the Latin abbreviation “lb,” for the Roman term libra pondo, or “pound weight.” Like many standard abbreviations of that period, “lb” was written with the addition of a horizontal bar, known as a tittle, or tilde (an example is shown above, right, in Johann Conrad Barchusen’s “Pyrosophia,” from 1698). And though printers commonly cast this barred abbreviation as a single character, it was the rushed pens of scribes that eventually produced the symbol’s modern form: hurriedly dashed off again and again, the barred “lb” mutated into the abstract #. The symbol shown here on the left, a barred “lb” rendered in Isaac Newton’s elegant scrawl, is a missing link, a now-extinct ancestor of the # that bridges the gap between the symbol’s Latin origins and its familiar modern form. Though it is now referred to by a number of different names—“hash mark,” “number sign,” and even “octothorpe,” a jokey appellation coined by engineers working on the Touch-Tone telephone keypad—the phrase “pound sign” can be traced to the symbol’s ancient origins. For just as “lb” came from libra, so the word “pound” is descended from pondo, making the # a descendent of the Roman term libra pondo in both name and appearance.

Pilcrow (¶)

Before there was any other punctuation there was the paragraphos—from the Greek para-, “beside,” and graphein, “write”—a precursor to the paragraph mark known as the pilcrow. A simple horizontal stroke placed in the left margin beside a line of text, the paragraphos was used in ancient Greece to call attention to conceptual changes in an otherwise unbroken block of text: a new topic, perhaps, or a new stanza in a poem. The paragraphos was a crude instrument: it was up to the reader to divine precisely why it had been employed in a given line. With the dawn of the first millennium, the paragraphos evolved, with some writers using the symbols Γ and γ, and others using outdented or enlarged letters to mark the beginning of each paragraph. Other writers began to insert the letter “K” for kaput, the Latin word for “head,” to demarcate sections of text. The use of “K” persisted, even as the Etruscan “K” faded in favor of the Roman “C,” until, by the twelfth century, kaput became replaced by capitulum—“little head,” or “chapter,” in Latin. The “C” became a new paragraph mark enthusiastically adopted by monks, whose ecclesiastical documents produced early examples of the modern chapter. Decorated with a vertical bar (shown here, in “Rudimenta Grammaticæ,” from 1500), “C” appeared as ¢ and, later, ¶; concurrently, paragraphos gave way to the Old French paragraphe, then to the Middle English pylcrafte, and, finally, to its modern name, “pilcrow.”

Ampersand (&)

The first recorded ampersand—a rudimentary ligature of the letters “E” and “T” from the Latin word et, meaning “and”—was scratched onto a Pompeian wall by an anonymous graffiti artist around the first century A.D. (shown above, image one). In time, the ampersand became a ubiquitous symbol: by the nineteenth century it was taught to schoolchildren as a twenty-seventh letter of the alphabet. Before that, however, it spent an entire millennium in competition with a rival mark. The “Tironian et” (⁊), had the twofold advantage of a head start and an impeccable pedigree. Created in the first century B.C. by Tiro, secretary to Rome’s famous orator Cicero, it was well established as part of Tiro’s extensive shorthand system, the notae Tironianae, by the time the proto-ampersand arrived a century later. The Tironian et continued to thrive in the Gothic-script religious texts of the Middle Ages but eventually fell out of use, along with the rest of Tiro’s system. The ampersand, meanwhile, evolved, as newly legible Roman and italic scripts made their way from Renaissance Italy, eventually assuming its familiar form (above, right, forty-five through forty-eight). Nowadays, the ampersand is everywhere—except in Ireland, where observant motorists may still spot a Tironian et adorning the occasional Gaelic traffic sign.