The term ampersand is a corruption of and (&) per se and, which literally means "(the character) & by itself (is the word) and." The symbol & is derived from the ligature of ET or et, which is the Latin word for "and."
Traditionally, when reciting the alphabet in English-speaking schools, any letter that could also be used as a word in itself ("A", "I", and, "O") was repeated with the Latin expression per se ("by itself"), as in "A per se A". It was also common practice to add the & sign at the end of the alphabet as if it were the 27th letter, pronounced as the Latin et or later in English as and. As a result, the recitation of the alphabet would end in "X, Y, Z, and per se and". This last phrase was routinely slurred to "ampersand" and the term had entered common English usage by 1837.
The ampersand can be traced back to the 1st century A.D. and the Old Roman cursive, in which the letters E and T occasionally were written together to form a ligature (Evolution of the ampersand – figure 1). In the later and more flowing New Roman Cursive, ligatures of all kinds were extremely common; figures 2 and 3 from the middle of 4th century are examples of how the et-ligature could look in this script. During the later development of the Latin script leading up to Carolingian minuscule (9th century) the use of ligatures in general diminished. The et-ligature, however, continued to be used and gradually became more stylized and less revealing of its origin (figures 4–6).
The modern italic type ampersand is a kind of "et" ligature that goes back to the cursive scripts developed during the Renaissance. After the advent of printing in Europe in 1455, printers made extensive use of both the italic and Roman ampersands. Since the ampersand's roots go back to Roman times, many languages that use a variation of the Latin alphabet make use of it.
The ampersand often appeared as a character at the end of the Latin alphabet, as for example in Byrhtferð's list of letters from 1011. Similarly, & was regarded as the 27th letter of the English alphabet, as taught to children in the US and elsewhere. An example may be seen in M. B. Moore's 1863 book The Dixie Primer, for the Little Folks. In her 1859 novel Adam Bede, George Eliot refers to this when she makes Jacob Storey say: "He thought it [Z] had only been put to finish off th' alphabet like; though ampusand would ha' done as well, for what he could see." The popular nursery rhyme Apple Pie ABC finishes with the lines "X, Y, Z, and ampersand, All wished for a piece in hand".
The ampersand should not be confused with the Tironian "et" ⁊, which has the same meaning, but which in appearance resembles the numeral 7. Both symbols have their roots in the classical antiquity, and both signs were used throughout the Middle Ages as a representation for the Latin word et ("and"). However, while the ampersand was in origin a common ligature in everyday script, the Tironian et was part of a highly specialised stenographic shorthand. The Tironian et (⁊) is found in Old Irish language script, a Latin-based script generally only used for decorative purposes today, where it signifies agus ("and") in Irish. This symbol may have entered the script language by way of monastic influence in the time of the early Christian church in Ireland.
In everyday handwriting, the ampersand is sometimes simplified in design as a large lowercase epsilon Ɛ or a reversed numeral 3, superimposed by a vertical line. The ampersand is also sometimes shown as an epsilon with a vertical line above and below it or a dot above and below it.
Ampersands are commonly seen in business names formed from partnership of two or more people, such as Johnson & Johnson, Dolce & Gabbana, Marks & Spencer, and Tiffany & Co., as well as some abbreviations containing the word and, such as AT&T (American Telephone and Telegraph), A&P (supermarkets), R&D (research and development), D&B (drum and bass), R&B (rhythm and blues), B&B (bed and breakfast), and P&L (profit and loss).
In film credits for stories, screenplays, etc., & indicates a closer collaboration than and. The ampersand is used by the Writers Guild of America to denote two writers collaborating on a specific script, rather than one writer rewriting another's work. In screenplays, two authors joined with & collaborated on the script, while two authors joined with and worked on the script at different times and may not have consulted each other at all. In the latter case, they both contributed enough significant material to the screenplay to receive credit but did not work together.
In APA style, the ampersand is used when citing sources in text such as (Jones & Jones, 2005). In the list of references, an ampersand precedes the last author's name when there is more than one author. (This does not apply to MLA style, which calls for the "and" to be spelled.)
The phrase et cetera ("and so forth"), usually written as etc. can be abbreviated &c. representing the combination et + c(etera).
The ampersand can be used to indicate that the "and" in a listed item is a part of the item's name and not a separator (e.g. "Rock, pop, rhythm & blues, and hip hop").
The ampersand may still be used as an abbreviation for "and" in informal writing regardless of how "and" is used.
The last six of these are carryovers from the Wingdings fonts, and are meant only for backward compatibility with those fonts.
On the QWERTY keyboard layout, the ampersand is ⇧ Shift+7. It is almost always available on keyboard layouts, sometimes on ⇧ Shift+6 or ⇧ Shift+8. On the AZERTY keyboard layout, & is an unmodified keystroke, positioned above A.
In the 20th century, following the development of formal logic, the ampersand became a commonly used logical notation for the binary operator or sentential connective AND. This usage was adopted in computing.
In Pascal, the
& as the first character of an identifier prevents the compiler from treating it as a keyword, thus escaping it.
Ampersand is the string concatenation operator in many BASIC dialects, AppleScript, Lingo, HyperTalk, and FileMaker. In Ada it applies to all one-dimensional arrays, not just strings.
The ampersand was occasionally used as a prefix to denote a hexadecimal number, such as
&FF for decimal 255, for instance in BBC BASIC. (The modern convention is to use "x" as a prefix to denote hexadecimal, thus
xFF.) Some other languages, such as the Monitor built into ROM on the Commodore 128, used it to indicate octal instead, a convention that spread throughout the Commodore community and is now used in the VICE emulator.
In MASM 80x86 Assembly Language,
& is the Substitution Operator, which tells the assembler to replace a macro parameter or text macro name with its actual value.
In SGML, XML, and HTML, the ampersand is used to introduce an SGML entity, such as
(for non-breaking space) or
α (for the Greek letter α). The HTML and XML encoding for the ampersand character is the entity
&. This can create a problem known as delimiter collision when converting text into one of these markup languages. For instance, when putting URLs or other material containing ampersands into XML format files such as RSS files the & must be replaced with & or they are considered not well formed, and computers will be unable to read the files correctly. SGML derived the use from IBM Generalized Markup Language, which was one of many IBM-mainframe languages to use the ampersand to signal a text substitution, eventually going back to System/360 macro assembly language.
In Microsoft Windows menus, labels, and other captions, the ampersand is used to denote the next letter as a keyboard shortcut (called an "Access key" by Microsoft). For instance setting a button label to
"&Print" makes it display as Print and for Alt+P to be a shortcut equivalent to pressing that button. A double ampersand is needed in order to display a real ampersand. This convention originated in the first WIN32 api, and is used in Windows Forms, (but not WPF, which uses underscore _ for this purpose) and is also copied into many other toolkits on multiple operating systems. Sometimes this causes problems similar to other programs that fail to sanitize markup from user input, for instance Navision databases have trouble if this character in either "Text" or "Code" fields.
The generic URL (Uniform Resource Locator) syntax allows for a query string to be appended to a file name in a web address so that additional information can be passed to a script; the question mark, or query mark, ?, is used to indicate the start of a query string. A query string is usually made up of a number of different name–value pairs, each separated by the ampersand symbol, &. For example,