Traditionally, in English-speaking schools when reciting the Alphabet, any letter that could also be used as a word in itself ("A," "I," "&" and, at one point, "O") was preceded by the Latin expression "per se" (Latin for "by itself"). Also, it was common practice to add at the end of the alphabet the "&" sign, pronounced "and". Thus, 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 crept into common English usage by around 1837.
Through folk etymology, the word ampersand has sometimes been falsely interpreted as "Amper's and", giving rise to the notion that the sign was invented, or at least popularised, by a certain Mr. Amper.
The ampersand symbol has been found on ancient Roman sources dating to the first century A.D. During this period the symbol was a boxy-looking ligature of the capital letter E and lower case t. Over time the figure became more curved and flowing, until it came to resemble something like the right hand figure to the left, often called the "italic" ampersand.
According to the Online Etymological Dictionary , the symbol "comes from an old Roman system of shorthand signs (ligatures), attested in Pompeiian graffiti, but not (as sometimes stated) from the Tironian Notes, which was a different form of shorthand, probably invented by Cicero's companion Marcus Tullius Tiro, which used a different symbol, something like a reversed gamma, to indicate et. This Tironian symbol was maintained by some medieval scribes, including Anglo-Saxon chroniclers, who sprinkled their works with a symbol like a numeral 7 to indicate the word and."
By the eighth century AD, Western calligraphy was well developed, particularly in forms such as Uncial, Insular script, and Carolingian minuscule. The calligraphers made extensive use of the ampersand because the condensation of a word into a single character made their work easier. During this time the even more condensed ampersand, shown above on the left, was developed. It is often called the "Roman" ampersand.
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 letter 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. Until recent times the alphabets used by children (in the USA) terminated not with Z but with & or related typographic symbols. (An example may be seen in M. B. Moore's 1863 book The Dixie Primer, for the Little Folks ). George Eliot refers to this when she has 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 conventional ampersand can be easily drawn by first making the cross stroke a bit farther to the right than where a common letter begins, shifting the pen to the center of this stroke, and then following the loop around.
In everyday handwriting, the ampersand is sometimes simplified to a ε superimposed by a vertical line, like a $ sign; this, too, seems to be a contraction of the Latin et. Sometimes it appears as nothing more than a "+" sign, or a t with a loop (a remnant of a lowercase e). This type of ampersand may actually be a rendering of the "+" sign, or of the Tironian "et". These forms are all generally acceptable and recognized, but some might view them as sloppy or casual.
Despite the symbol's declining use, it can still be useful when space is limited. Perhaps due to its increasing rarity, the ampersand is sometimes rendered incorrectly when drawn by hand. The most common error is to render the symbol backwards Another mistake that is sometimes made is to draw it as a treble clef from musical notation.
The main surviving use of the ampersand is in the formal names of businesses (especially firms and partnerships, particularly law firms, architectural firms, and stockbroker firms). When the ampersand forms part of a registered name (e.g. Brown & Watson); it should not be replaced with and.
With the growth of mobile phone usage and text messaging, the ampersand is gaining new use in SMS language both as a representation for the word "and" and in rebus form, such as "pl&" in place of the word "planned".
The ampersand is also often used when addressing an envelope to a couple: "Mr. & Mrs. Jones" or "John & Silvia".
The ampersand is also used for book and movie titles, such as Harry & Tonto, as well, and in some other proper names. In these cases, & is interchangeable with the word and; the distinction between them is mostly aesthetic. However, in film credits for story, screenplay, etc., & indicates a closer collaboration than and; in screenplays, for example, 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 APA style the ampersand is used when citing sources in text such as (Jones & Jones, 2005).
The phrase et cetera ("and so forth"), usually written as etc. can be abbreviated &c. representing the combination et + c(etera). This usage is frequently seen in writings of the 18th and 19th centuries, but is rare in modern usage.
In the twentieth 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.
There are two common uses for the "&" symbol as a binary operator in programming languages: as the logical AND operator, and as the string or array concatenation operator. There are also various idiosyncratic uses of & by various languages, for example as a short form of the verb PRINT in BASIC-PLUS on the DEC PDP-11.
Many languages with syntax derived from C differentiate between:
In C and C++, "&" is also used as an unary prefix operator, denoting the address in memory of the argument, e.g.
&x, &func, &a. (This is called "referencing".) In C++, unary prefix & in a formal parameter of a function denotes pass-by-reference.
Ampersand is the string concatenation operator in Ada, AppleScript, HyperTalk, FileMaker scripting language and many BASIC dialects. In Ada, it applies to all one-dimensional arrays, not just strings.
In some BASIC dialects, unary suffix & denotes a variable is of type long, or 32 bits in length. In BBC BASIC, unary prefix ampersand marks an integer literal written in hexadecimal; it served a similar function in the Monitor built into ROM on the Commodore 128, but indicated octal instead, a convention that spread throughout the Commodore community and is now used in the VICE emulator.
In MySQL the '&' has dual roles. As a logical AND in addition it serves a bitwise operator of an intersection between elements.
When found at the end of a Unix shell command, the ampersand indicates that the indicated command is to be processed in the background. Two ampersands means that the next command should only be evaluated if the current one exits with a zero status.
In SGML, XML, and HTML, the ampersand is used to introduce an SGML entity. The HTML and XML encoding for the ampersand character is the entity '&'. This creates what is known as the ampersand problem. For instance, when putting URLs or other material containing ampersands into XML format files such as RSS files the amp; has to be added to the & or they are considered not well formed and computers will be unable to read the files correctly. When working with large quantities of text this can be very problematic.
The ampersand is occasionally used as a prefix to denote a hexadecimal (base 16) number, such as &FF for decimal 255.
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, www.example.com/login.php?username=test&password=blank. But see also "Ampersands in URI attribute values"