The asterisk ( *), from Late Latin asteriscus, from Ancient Greek ἀστερίσκος, asteriskos, "little star", is a typographical symbol. It is so called because it resembles a conventional image of a heraldic star. Computer scientists and mathematicians often vocalize it as star (as, for example, in the A* search algorithm or C*-algebra). An asterisk is usually five- or six-pointed in print and six- or eight-pointed when handwritten, though more complex forms exist. Its most common use is to call out a footnote. It is also often used to censor offensive words. In computer science, the asterisk is commonly used as a wildcard character, or to denote pointers, repetition, or multiplication.

History

The asterisk was already in use as a symbol in ice age cave paintings. There is also a two-thousand-year-old character used by Aristarchus of Samothrace called the asteriskos, ※, which he used when proofreading Homeric poetry to mark lines that were duplicated. Origen is known to have also used the asteriskos to mark missing Hebrew lines from his Hexapla. The asterisk evolved in shape over time, but its meaning as a symbol used to correct defects remained. In the Middle Ages, the asterisk was used to emphasize a particular part of text, often linking those parts of the text to a marginal comment. However, an asterisk was not always used. One hypothesis to the origin of the asterisk is that it stems from the 5000-year-old Sumerian character dingir, 𒀭, though this hypothesis seems to only be based on visual appearance.

Usage

Censorship

When toning down expletives, asterisks are often used to replace letters. For example, the word "badword" might become "bard", "bd", "b****" or even "". Vowels tend to be censored with an asterisk more than consonants, but the intelligibility of censored profanities with multiple syllables such as "bdwrd" and "bd" or "ba****d", or uncommon ones is higher if put in context with surrounding text. When a document containing classified information is published, the document may be "sanitized" (redacted) by replacing the classified information with asterisks. For example, the Intelligence and Security Committee Russia report.

Competitive sports and games

In colloquial usage, an asterisk attached to a sporting record indicates that it is somehow tainted. This is because results that have been considered dubious or set aside are recorded in the record books with an asterisk rendering to a footnote explaining the reason or reasons for concern.

Baseball

The usage of the term in sports arose during the 1961 baseball season in which Roger Maris of the New York Yankees was threatening to break Babe Ruth's 34-year-old single-season home run record. Ruth had amassed 60 home runs in a season with only 154 games, but Maris was playing the first season in the American League's newly expanded 162-game season. Baseball Commissioner Ford C. Frick, a friend of Ruth's during the legendary slugger's lifetime, held a press conference to announce his "ruling" that should Maris take longer than 154 games both records would be acknowledged by Major League Baseball, but that some "distinctive mark" [his term] be placed next to Maris', which should be listed alongside Ruth's achievement in the "record books". The asterisk as such a mark was suggested at that time by New York Daily News sportswriter Dick Young, not Frick. The reality, however, was that MLB actually had no direct control over any record books until many years later, and it all was merely a suggestion on Frick's part. Within a few years the controversy died down and all prominent baseball record keepers listed Maris as the single-season record holder for as long as he held the record. Nevertheless, the stigma of holding a tainted record remained with Maris for many years, and the concept of a real or figurative asterisk denoting less-than-accepted "official" records has become widely used in sports and other competitive endeavors. A 2001 TV movie about Maris's record-breaking season was called 61* (pronounced sixty-one asterisk) in reference to the controversy. Uproar over the integrity of baseball records and whether or not qualifications should be added to them arose again in the late 1990s, when a steroid-fueled power explosion led to the shattering of Maris' record. Even though it was obvious - and later admitted - by Mark McGwire that he was heavily on steroids when he hit 70 home runs in 1998, ruling authorities did nothing - to the annoyance of many fans and sportswriters. Three years later self-confessed steroid-user Barry Bonds pushed that record out to 73, and fans once again began to call for an asterisk in the sport's record books. Fans were especially critical and clamored louder for baseball to act during the 2007 season, as Bonds approached and later broke Hank Aaron's career home run record of 755. The Houston Astros' 2017 World Series win was marred after an investigation by MLB revealed the team's involvement in a sign-stealing scheme during that season. Fans, appalled by what they perceived to be overly lenient discipline against the Astros players, nicknamed the team the "Houston Asterisks". In recent years, the asterisk has come into use on baseball scorecards to denote a "great defensive play."

Usage in anti-doping campaigns

Cricket

Other sports

During the first decades of the 21st century, the term asterisk to denote a tainted accomplishment caught on in other sports first in North America and then, due in part to North American sports' widespread media exposure, around the world.

Computing

Computer science

Computer interfaces

Adding machines and printing calculators

Programming languages

Many programming languages and calculators use the asterisk as a symbol for multiplication. It also has a number of special meanings in specific languages, for instance:

Comments in programming languages

In the B programming language and languages that borrow syntax from it, such as C, PHP, Java, or C#, comments in the source code (for information to people, ignored by the compiler) are marked by an asterisk combined with the slash: Some Pascal-like programming languages, for example, Object Pascal, Modula-2, Modula-3, and Oberon, as well as several other languages including ML, Wolfram Language (Mathematica), AppleScript, OCaml, Standard ML, and Maple, use an asterisk combined with a parenthesis: CSS also uses the slash-star comment format. Each computing language has its own way of handling comments; /* ... */ and similar notations are not universal.

History of information technology

The asterisk was a supported symbol on the IBM 026 Keypunch (introduced in 1949 and used to create punch cards with data for early computer systems). It was also included in the FIELDATA character encoding and the ASCII standard.

Economics

Education

Fluid mechanics

In fluid mechanics an asterisk in superscript is sometimes used to mean a property at sonic speed.

Games

Human genetics

Linguistics

In linguistics, an asterisk may be used for a range of purposes depending on what is being discussed. The symbol is used to indicate reconstructed words of proto-languages (for which there are no records). For modern languages, it may be placed before posited problematic word forms, phrases or sentences to flag that they are hypothetical, ungrammatical, unpronounceable, etc. Historical linguist August Schleicher is cited as first using the asterisk for linguistic purposes, specifically for unattested forms that are linguistic reconstructions. Using the asterisk for descriptive and not just historical purposes arose in the 20th century. By analogy with its use in historical linguistics, the asterisk was variously prepended to "hypothetical" or "unattested" elements in modern language. Its usage also expanded to include "non-existent" or "impossible" forms. Leonard Bloomfield (1933) uses the asterisk with forms such as cran, impossible to occur in isolation: cran- only occurs within the compound cranberry. Such usage for a "non-existent form" was also found in French, German and Italian works in the middle of the 20th century. Asterisk usage in linguistics later came to include not just impossible forms, but "ungrammatical sentences", those that are "ill formed for the native speaker". The expansion of asterisk usage to entire sentences is often credited to Noam Chomsky, but Chomsky in 1968 already describes this usage as "conventional". Linguist Fred Householder claims some credit, but Giorgio Graffi argues that using an asterisk for this purpose predates his works. The meaning of the asterisk usage in specific linguistic works may go unelucidated so can be unclear. Linguistics sometimes uses double asterisks (**), another symbol such as the question mark, or both symbols (e.g. ?) to indicate degrees of unacceptability.

Historical linguistics

In historical linguistics, the asterisk marks words or phrases that are not directly recorded in texts or other media, and that are therefore reconstructed on the basis of other linguistic material by the comparative method. In the following example, the Proto-Germanic word ainlif is a reconstructed form. A double asterisk (**) sometimes indicates an intermediary or proximate reconstructed form (e.g. a single asterisk for reconstructed thirteenth century Chinese and a double asterisk for reconstructions of older Ancient Chinese or a double asterisk for proto-Popolocan and a single asterisk for intermediary forms ). In other cases, the double asterisk denotes a form that would be expected according to a rule, but is not actually found. That is, it indicates a reconstructed form that is not found or used, and in place of which another form is found in actual usage:

Ungrammaticality

In most areas of linguistics, but especially in syntax, an asterisk in front of a word or phrase indicates that the word or phrase is not used because it is ungrammatical. An asterisk before a parenthesis indicates that the lack of the word or phrase inside is ungrammatical, while an asterisk after the opening bracket of the parenthesis indicates that the existence of the word or phrase inside is ungrammatical—e.g., the following indicates "go the station" would be ungrammatical: Use of an asterisk to denote forms or sentences that are ungrammatical is often complemented by the use of the question mark (?) to indicate a word, phrase or sentence that is avoided, questionable or strange, but not necessarily outright ungrammatical. Other sources go further and use several symbols (e.g. the asterisk, question mark, and degree symbol °) to indicate gradations or a continuum of acceptability.

Ambiguity

Since a word marked with an asterisk could mean either "unattested" or "impossible", it is important in some contexts to distinguish these meanings. In general, authors retain asterisks for "unattested", and prefix x, **, †, or ? for the latter meaning. An alternative is to append the asterisk (or another symbol, possibly to differentiate between even more cases) at the end.

Optimality theory

In optimality theory, asterisks are used as "violation marks" in tableau cells to denote a violation of a constraint by an output form.

Phonetic transcription

In phonetic transcription using the International Phonetic Alphabet and similar systems, an asterisk was historically used to denote that the word it preceded was a proper noun. See this example from W. Perrett's 1921 transcription of Gottfried Keller's Das Fähnlein der sieben Aufrechten: This convention is no longer usual.

Mathematics

The asterisk has many uses in mathematics. The following list highlights some common uses and is not exhaustive. The asterisk is used in all branches of mathematics to designate a correspondence between two quantities denoted by the same letter – one with the asterisk and one without.

Mathematical typography

In fine mathematical typography, the Unicode character (in HTML, ∗; not to be confused with ) is available. This character also appeared in the position of the regular asterisk in the PostScript symbol character set in the Symbol font included with Windows and Macintosh operating systems and with many printers. It should be used for a large asterisk that lines up with the other mathematical operators, sitting on the math centerline rather than on the text baseline.

Music

Religious texts

Star of Life

A Star of Life, a six-bar asterisk overlaid with the Rod of Asclepius (the symbol of health), may be used as an alternative to cross or crescent symbols on ambulances.

Statistical results

In many scientific publications, the asterisk is employed as a shorthand to denote the statistical significance of results when testing hypotheses. When the likelihood that a result occurred by chance alone is below a certain level, one or more asterisks are displayed. Popular significance levels are <0.05 (), <0.01 (), and <0.001 ().

Telephony

On a tone dialling telephone keypad, the asterisk (called star) is one of the two special keys (the other is the 'square key – almost invariably replaced by the number sign # (called 'pound sign' (US), 'hash' (other countries), or 'hex'), and is found to the left of the zero ). They are used to navigate menus in systems such as voice mail, or in vertical service codes.

Typography

Encodings

The Unicode standard has a variety of asterisk-like characters, compared in the table below. (Characters will display differently in different browsers and fonts.) The reason there are so many is chiefly because of the controversial decision to include in Unicode the entire Zapf Dingbats symbol font.