vertical bar

TheInfoList

OR:

The vertical bar, , is a
glyph A glyph () is any kind of purposeful mark. In typography, a glyph is "the specific shape, design, or representation of a character". It is a particular graphical representation, in a particular typeface, of an element of written language. A ...
with various uses in
mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...
,
computing Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, e ...
, and
typography Typography is the art and technique of arranging type to make written language legible, readable and appealing when displayed. The arrangement of type involves selecting typefaces, point sizes, line lengths, line-spacing ( leading), a ...
. It has many names, often related to particular meanings: Sheffer stroke (in
logic Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the science of deductively valid inferences or of logical truths. It is a formal science investigating how conclusions follow from premise ...
), pipe, bar, or (literally the word "or"), vbar, and others.

# Usage

## Mathematics

The vertical bar is used as a mathematical symbol in numerous ways: *
absolute value In mathematics, the absolute value or modulus of a real number x, is the non-negative value without regard to its sign. Namely, , x, =x if is a positive number, and , x, =-x if x is negative (in which case negating x makes -x positive), an ...
: $, x,$, read "the ''absolute value'' of ''x''" *
cardinality In mathematics, the cardinality of a set is a measure of the number of elements of the set. For example, the set A = \ contains 3 elements, and therefore A has a cardinality of 3. Beginning in the late 19th century, this concept was generalized ...
: $, S,$, read "the ''cardinality'' of the
set Set, The Set, SET or SETS may refer to: Science, technology, and mathematics Mathematics *Set (mathematics), a collection of elements *Category of sets, the category whose objects and morphisms are sets and total functions, respectively Electro ...
''S''" *
conditional probability In probability theory, conditional probability is a measure of the probability of an event occurring, given that another event (by assumption, presumption, assertion or evidence) has already occurred. This particular method relies on event B occur ...
: $P\left(X, Y\right)$, reads "the
probability Probability is the branch of mathematics concerning numerical descriptions of how likely an event is to occur, or how likely it is that a proposition is true. The probability of an event is a number between 0 and 1, where, roughly speaking ...
of ''X'' ''given'' ''Y''" *
determinant In mathematics, the determinant is a scalar value that is a function of the entries of a square matrix. It characterizes some properties of the matrix and the linear map represented by the matrix. In particular, the determinant is nonzero if an ...
: $, A,$, read "the ''determinant'' of the
matrix Matrix most commonly refers to: * ''The Matrix'' (franchise), an American media franchise ** ''The Matrix'', a 1999 science-fiction action film ** "The Matrix", a fictional setting, a virtual reality environment, within ''The Matrix'' (franchis ...
''A''". When the matrix entries are written out, the determinant is denoted by surrounding the matrix entries by vertical bars instead of the usual brackets or parentheses of the matrix, as in $\begin a & b \\ c & d\end$. *
distance Distance is a numerical or occasionally qualitative measurement of how far apart objects or points are. In physics or everyday usage, distance may refer to a physical length or an estimation based on other criteria (e.g. "two counties over"). ...
: $P, ab$, denoting the shortest ''distance'' between point $P$ to line $ab$, so line $P, ab$ is perpendicular to line $ab$ * divisibility: $a \mid b$, read "''a'' ''divides'' ''b''" or "''a'' is a ''factor'' of ''b''", though Unicode also provides special 'divides' and 'does not divide' symbols (U+2223 and U+2224: ∣, ∤) * function evaluation: $f\left(x\right), _$, read "''f'' of ''x'', evaluated at ''x'' equals 4" (see subscripts at Wikibooks) * length: $, s,$, read "the ''length'' of the
string String or strings may refer to: * String (structure), a long flexible structure made from threads twisted together, which is used to tie, bind, or hang other objects Arts, entertainment, and media Films * ''Strings'' (1991 film), a Canadian ani ...
''s''" *
norm Naturally occurring radioactive materials (NORM) and technologically enhanced naturally occurring radioactive materials (TENORM) consist of materials, usually industrial wastes or by-products enriched with radioactive elements found in the envir ...
: $, \mathbf,$, read "the ''norm'' of the (greater-than-one-dimensional) vector $\mathbf$" (note that absolute value is a one-dimensional norm), although a double vertical bar (see below) is more often used to avoid ambiguity. * order: $, G,$, read "the ''order'' of the group ''G''" * restriction: $f, _$, denoting the ''restriction'' of the function $f$, with a domain that is a superset of $A$, to just $A$ *
set-builder notation In set theory and its applications to logic, mathematics, and computer science, set-builder notation is a mathematical notation for describing a set by enumerating its elements, or stating the properties that its members must satisfy. Defining ...
: $\$, read "the set of ''x'' ''such that'' ''x'' is less than two". Often, a colon ':' is used instead of a vertical bar * the Sheffer stroke in
logic Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the science of deductively valid inferences or of logical truths. It is a formal science investigating how conclusions follow from premise ...
: $a, b$, read "''a'' ''nand'' ''b''" *
subtraction Subtraction is an arithmetic operation that represents the operation of removing objects from a collection. Subtraction is signified by the minus sign, . For example, in the adjacent picture, there are peaches—meaning 5 peaches with 2 take ...
: $f\left(x\right) \vert _a ^b$, read "''f(x)'' ''from'' ''a'' ''to'' ''b''", denoting $f\left(b\right) - f\left(a\right)$. Used in the context of a definite integral with variable ''x''. * A vertical bar can be used to separate variables from fixed parameters in a function, for example $f\left(x, \mu,\sigma\right)$, or in the notation for
elliptic integrals In integral calculus, an elliptic integral is one of a number of related functions defined as the value of certain integrals, which were first studied by Giulio Fagnano and Leonhard Euler (). Their name originates from their originally arising ...
. The double vertical bar, $\,$, is also employed in mathematics. * parallelism: $AB \parallel CD$, read "the line $AB$ ''is parallel to'' the line $CD$" *
Norm Naturally occurring radioactive materials (NORM) and technologically enhanced naturally occurring radioactive materials (TENORM) consist of materials, usually industrial wastes or by-products enriched with radioactive elements found in the envir ...
: $\, \mathbf\,$, read "the ''norm'' (length, size, magnitude etc.) of the
vector Vector most often refers to: *Euclidean vector, a quantity with a magnitude and a direction *Vector (epidemiology), an agent that carries and transmits an infectious pathogen into another living organism Vector may also refer to: Mathematic ...
x". People sometimes use two single bars in analogy to the absolute value, which is a one-dimensional norm. * Propositional truncation (a type former that truncates a type down to a mere proposition in homotopy type theory): for any $a : A$ (read "term $a$ of type $A$") we have $, a, : \left\, A \right\,$ (here $, a,$ reads "''
image An image is a visual representation of something. It can be two-dimensional, three-dimensional, or somehow otherwise feed into the visual system to convey information. An image can be an artifact, such as a photograph or other two-dimension ...
'' of $a : A$ in $\left\, A \right\,$" and $, a, : \left\, A \right\,$ reads "''propositional truncation'' of $A$") In
LaTeX Latex is an emulsion (stable dispersion) of polymer microparticles in water. Latexes are found in nature, but synthetic latexes are common as well. In nature, latex is found as a milky fluid found in 10% of all flowering plants (angios ...
mathematical mode, the ASCII vertical bar produces a vertical line, and \,  creates a double vertical line (a , b \, c is set as $a , b \, c$). This has different spacing from \mid and \parallel, which are
relational operator In computer science, a relational operator is a programming language construct or operator that tests or defines some kind of relation between two entities. These include numerical equality (''e.g.'', ) and inequalities (''e.g.'', ). In pr ...
s: a \mid b \parallel c is set as $a \mid b \parallel c$. See below about LaTeX in text mode.

## Physics

The vertical bar is used in bra–ket notation in
quantum physics Quantum mechanics is a fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles. It is the foundation of all quantum physics including quantum chemistry, q ...
. Examples: * $, \psi\rangle$: the quantum physical state $\psi$ * $\langle\psi,$: the dual state corresponding to the state above * $\langle\psi, \rho\rangle$: the inner product of states $\psi$ and $\rho$ * Supergroups in physics are denoted ''G''(''N'', ''M''), which reads "''G'', ''M'' vertical bar ''N''"; here ''G'' denotes any supergroup, ''M'' denotes the bosonic dimensions, and ''N'' denotes the Grassmann dimensions.

## Computing

### Pipe

A pipe is an
inter-process communication In computer science, inter-process communication or interprocess communication (IPC) refers specifically to the mechanisms an operating system provides to allow the processes to manage shared data. Typically, applications can use IPC, categori ...
mechanism originating in
Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and ...
, which directs the output (standard out and, optionally, standard error) of one process to the input (standard in) of another. In this way, a series of commands can be "piped" together, giving users the ability to quickly perform complex multi-stage processing from the
command line A command-line interpreter or command-line processor uses a command-line interface (CLI) to receive commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invoking executables and pro ...
or as part of a Unix shell script ("bash file"). In most
Unix shell A Unix shell is a command-line interpreter or shell that provides a command line user interface for Unix-like operating systems. The shell is both an interactive command language and a scripting language, and is used by the operating system ...
s (command interpreters), this is represented by the vertical bar character. For example:  grep grep is a command-line utility for searching plain-text data sets for lines that match a regular expression. Its name comes from the ed command ''g/re/p'' (''globally search for a regular expression and print matching lines''), which has the sam ... -i 'blair' filename.log , more  where the output from the grep process (all lines containing 'blair') is piped to the more process (which allows a command line user to read through results one page at a time). The same "pipe" feature is also found in later versions of DOS and Microsoft Windows. This usage has led to the character itself being called "pipe".

### Disjunction

In many programming languages, the vertical bar is used to designate the logic operation ''or'', either bitwise ''or'' or
logical Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the science of deductively valid inferences or of logical truths. It is a formal science investigating how conclusions follow from premises ...
''or''. Specifically, in C and other languages following
C syntax C, or c, is the third letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''cee'' (pronounced ), plural ''cees''. History "C" ...
conventions, such as
C++ C++ (pronounced "C plus plus") is a high-level general-purpose programming language created by Danish computer scientist Bjarne Stroustrup as an extension of the C programming language, or "C with Classes". The language has expanded signific ...
,
Perl Perl is a family of two high-level, general-purpose, interpreted, dynamic programming languages. "Perl" refers to Perl 5, but from 2000 to 2019 it also referred to its redesigned "sister language", Perl 6, before the latter's name was offic ...
,
Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mo ...
and C#, a , b denotes a bitwise ''or''; whereas a double vertical bar a , , b denotes a ( short-circuited) logical ''or''. Since the character was originally not available in all
code page In computing, a code page is a character encoding and as such it is a specific association of a set of printable characters and control characters with unique numbers. Typically each number represents the binary value in a single byte. (In some c ...
s and keyboard layouts, ANSI C can transcribe it in form of the trigraph ??!, which, outside string literals, is equivalent to the ,  character. In
regular expression A regular expression (shortened as regex or regexp; sometimes referred to as rational expression) is a sequence of characters that specifies a search pattern in text. Usually such patterns are used by string-searching algorithms for "find" ...
syntax, the vertical bar again indicates logical ''or'' ( alternation). For example: the Unix command grep grep is a command-line utility for searching plain-text data sets for lines that match a regular expression. Its name comes from the ed command ''g/re/p'' (''globally search for a regular expression and print matching lines''), which has the sam ... -E 'fu, bar' matches lines containing 'fu' or 'bar'.

### Concatenation

The double vertical bar operator ", , " denotes
string String or strings may refer to: * String (structure), a long flexible structure made from threads twisted together, which is used to tie, bind, or hang other objects Arts, entertainment, and media Films * ''Strings'' (1991 film), a Canadian ani ...
concatenation In formal language theory and computer programming, string concatenation is the operation of joining character strings end-to-end. For example, the concatenation of "snow" and "ball" is "snowball". In certain formalisations of concatenat ...
in
PL/I PL/I (Programming Language One, pronounced and sometimes written PL/1) is a procedural, imperative computer programming language developed and published by IBM. It is designed for scientific, engineering, business and system programming. I ...
, standard ANSI SQL, and theoretical computer science (particularly
cryptography Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or '' -logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adve ...
).

### Delimiter

Although not as common as commas or tabs, the vertical bar can be used as a
delimiter A delimiter is a sequence of one or more characters for specifying the boundary between separate, independent regions in plain text, mathematical expressions or other data streams. An example of a delimiter is the comma character, which acts ...
in a flat file. Examples of a pipe-delimited standard data format are LEDES 1998B and HL7. It is frequently used because vertical bars are typically uncommon in the data itself. Similarly, the vertical bar may see use as a delimiter for
regular expression A regular expression (shortened as regex or regexp; sometimes referred to as rational expression) is a sequence of characters that specifies a search pattern in text. Usually such patterns are used by string-searching algorithms for "find" ...
operations (e.g. in sed). This is useful when the regular expression contains instances of the more common forward slash (/) delimiter; using a vertical bar eliminates the need to escape all instances of the forward slash. However, this makes the bar unusable as the regular expression "alternative" operator.

### Backus–Naur form

In Backus–Naur form, an expression consists of sequences of symbols and/or sequences separated by ', ', indicating a
choice A choice is the range of different things from which a being can choose. The arrival at a choice may incorporate motivators and models. For example, a traveler might choose a route for a journey based on the preference of arriving at a give ...
, the whole being a possible substitution for the symbol on the left.

### Concurrency operator

In calculi of communicating processes (like pi-calculus), the vertical bar is used to indicate that processes execute in parallel.

### APL

The pipe in APL is the modulo or ''residue'' function between two operands and the absolute value function next to one operand.

### List comprehensions

The vertical bar is used for list comprehensions in some functional languages, e.g. Haskell and Erlang. Compare
set-builder notation In set theory and its applications to logic, mathematics, and computer science, set-builder notation is a mathematical notation for describing a set by enumerating its elements, or stating the properties that its members must satisfy. Defining ...
.

### Text markup

The vertical bar is used as a special character in
lightweight markup language A lightweight markup language (LML), also termed a simple or humane markup language, is a markup language with simple, unobtrusive syntax. It is designed to be easy to write using any generic text editor and easy to read in its raw form. Lightwei ...
s, notably
MediaWiki MediaWiki is a free and open-source wiki software. It is used on Wikipedia and almost all other Wikimedia websites, including Wiktionary, Wikimedia Commons and Wikidata; these sites define a large part of the requirement set for MediaWik ...
's
Wikitext A wiki ( ) is an online hypertext publication collaboratively edited and managed by its own audience, using a web browser. A typical wiki contains multiple pages for the subjects or scope of the project, and could be either open to the p ...
(in the templates and internal links). In LaTeX text mode, the vertical bar produces an
em dash The dash is a punctuation mark consisting of a long horizontal line. It is similar in appearance to the hyphen but is longer and sometimes higher from the baseline. The most common versions are the endash , generally longer than the hyphen b ...
(—). The \textbar command can be used to produce a vertical bar.

## Phonetics and orthography

In the
Khoisan languages The Khoisan languages (; also Khoesan or Khoesaan) are a group of African languages originally classified together by Joseph Greenberg. Khoisan languages share click consonants and do not belong to other African language families. For much of ...
and the
International Phonetic Alphabet The International Phonetic Alphabet (IPA) is an alphabetic system of phonetic notation based primarily on the Latin script. It was devised by the International Phonetic Association in the late 19th century as a standardized representation ...
, the vertical bar is used to write the
dental click Dental (or more precisely denti-alveolar) clicks are a family of click consonants found, as constituents of words, only in Africa and in the Damin ritual jargon of Australia. In English, the ''tut-tut!'' (British spelling, "tutting") or ''t ...
(). A double vertical bar is used to write the alveolar lateral click (). Since these are technically letters, they have their own
Unicode Unicode, formally The Unicode Standard,The formal version reference is is an information technology standard for the consistent encoding, representation, and handling of text expressed in most of the world's writing systems. The standard, ...
code points in the
Latin Extended-B Latin Extended-B is the fourth block (0180-024F) of the Unicode Standard. It has been included since version 1.0, where it was only allocated to the code points 0180-01FF and contained 113 characters. During unification with ISO 10646 for version ...
range: U+01C0 for the single bar and U+01C1 for the double bar. Some Northwest and
Northeast Caucasian languages The Northeast Caucasian languages, also called East Caucasian, Nakh-Daghestani or ''Vainakh-Daghestani'', is a family of languages spoken in the Russian republics of Dagestan, Chechnya and Ingushetia and in Northern Azerbaijan as well as ...
written in the
Cyrillic script , bg, кирилица , mk, кирилица , russian: кириллица , sr, ћирилица, uk, кирилиця , fam1 = Egyptian hieroglyphs , fam2 = Proto-Sinaitic , fam3 = Phoenician , fam4 = Gr ...
have a vertical bar called palochka ( rus, палочка, 5=little stick), indicating the preceding consonant is an ejective. Longer single and double vertical bars are used to mark
prosodic In linguistics, prosody () is concerned with elements of speech that are not individual phonetic segments (vowels and consonants) but are properties of syllables and larger units of speech, including linguistic functions such as intonation, st ...
boundaries in the IPA.

## Literature

### Punctuation

In medieval European manuscripts, a single vertical bar was a common variant of the virgula used as a
period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concep ...
, scratch comma,. and
caesura 300px, An example of a caesura in modern western music notation A caesura (, . caesuras or caesurae; Latin for " cutting"), also written cæsura and cesura, is a metrical pause or break in a verse where one phrase ends and another phrase begin ...
mark. In
Sanskrit Sanskrit (; attributively , ; nominally , , ) is a classical language belonging to the Indo-Aryan branch of the Indo-European languages. It arose in South Asia after its predecessor languages had diffused there from the northwest in the lat ...
and other Indian languages, a single vertical mark, a
danda In Indic scripts, the daṇḍa (Sanskrit: दण्ड ' "stick") is a punctuation mark. The glyph consists of a single vertical stroke. Use The daṇḍa marks the end of a sentence or line, comparable to a full stop (period) as commonly ...
, has a similar function as a period (full stop). Two bars , , (a 'double danda') is the equivalent of a
pilcrow The pilcrow, ¶, is a handwritten or typographical character used to identify a paragraph. It is also called the paragraph mark (or sign or symbol), paraph, or blind P. The pilcrow may be used at the start of separate paragraphs or ...
in marking the end of a
stanza In poetry, a stanza (; from Italian ''stanza'' , "room") is a group of lines within a poem, usually set off from others by a blank line or indentation. Stanzas can have regular rhyme and metrical schemes, but they are not required to have ei ...
, paragraph or section. The danda has its own Unicode code point, U+0964.

### Poetry

A double vertical bar or is the standard caesura mark in English
literary criticism Literary criticism (or literary studies) is the study, evaluation, and interpretation of literature. Modern literary criticism is often influenced by literary theory, which is the philosophical discussion of literature's goals and methods. Th ...
and analysis. It marks the strong break or
caesura 300px, An example of a caesura in modern western music notation A caesura (, . caesuras or caesurae; Latin for " cutting"), also written cæsura and cesura, is a metrical pause or break in a verse where one phrase ends and another phrase begin ...
common to many forms of
poetry Poetry (derived from the Greek ''poiesis'', "making"), also called verse, is a form of literature that uses aesthetic and often rhythmic qualities of language − such as phonaesthetics, sound symbolism, and metre − to evoke meanings i ...
, particularly Old English verse. It is also traditionally used to mark the division between lines of verse printed as prose (the style preferred by
Oxford University Press Oxford University Press (OUP) is the university press of the University of Oxford. It is the largest university press in the world, and its printing history dates back to the 1480s. Having been officially granted the legal right to print books ...
), though it is now often replaced by the forward slash.

### Notation

In the Geneva Bible and early printings of the
King James Version The King James Version (KJV), also the King James Bible (KJB) and the Authorized Version, is an English translation of the Christian Bible for the Church of England, which was commissioned in 1604 and published in 1611, by sponsorship of K ...
, a double vertical bar is used to mark margin notes that contain an alternative translation from the original text. These margin notes always begin with the conjunction "Or". In later printings of the King James Version, the double vertical bar is irregularly used to mark any comment in the margins.

### Music scoring

In music, when writing chord sheets, single vertical bars associated with a colon (, : A / / / :, ) represents the beginning and end of a section (e.g. Intro, Interlude, Verse, Chorus) of music. Single bars can also represent the beginning and end of measures (, : A / / / , D / / / , E / / / :, ). A double vertical bar associated with a colon can represent the repeat of a given section (, , : A / / / :, , - play twice).

# Encoding

## Solid vertical bar vs broken bar

Many early video terminals and dot-matrix printers rendered the vertical bar character as the
allograph Allography, from the Greek for "other writing", has several meanings which all relate to how words and sounds are written down. Authorship An allograph may be the opposite of an autograph – i.e. a person's words or name ( signature) written b ...
broken bar . This may have been to distinguish the character from the lower-case 'L' and the upper-case '' on these limited-resolution devices, and to make a vertical line of them look more like a horizontal line of dashes. It was also (briefly) part of the
ASCII ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because of ...
standard. An initial draft for a 7-bit character set that was published by the X3.2 subcommittee for Coded Character Sets and Data Format on June 8, 1961, was the first to include the vertical bar in a standard set. The bar was intended to be used as the representation for the
logical OR In logic, disjunction is a logical connective typically notated as \lor and read aloud as "or". For instance, the English language sentence "it is raining or it is snowing" can be represented in logic using the disjunctive formula R \lor S ...
symbol. A subsequent draft on May 12, 1966, places the vertical bar in column 7 alongside regional entry codepoints, and formed the basis for the original draft proposal used by the
International Standards Organisation The International Organization for Standardization (ISO ) is an international standard development organization composed of representatives from the national standards organizations of member countries. Membership requirements are given in Art ...
. This draft received opposition from the IBM user group SHARE, with its chairman, H. W. Nelson, writing a letter to the
American Standards Association The American National Standards Institute (ANSI ) is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organ ...
titled "The Proposed revised American Standard Code for Information Interchange does NOT meet the needs of computer programmers!"; in this letter, he argues that no characters within the international subset designated at columns 2-5 of the character set would be able to adequately represent logical OR and logical NOT in languages such as IBM's
PL/I PL/I (Programming Language One, pronounced and sometimes written PL/1) is a procedural, imperative computer programming language developed and published by IBM. It is designed for scientific, engineering, business and system programming. I ...
universally on all platforms. As a compromise, a requirement was introduced where the exclamation mark (!) and
circumflex The circumflex () is a diacritic in the Latin and Greek scripts that is also used in the written forms of many languages and in various romanization and transcription schemes. It received its English name from la, circumflexus "bent around" ...
(^) would display as logical OR (, ) and logical NOT (¬) respectively in use cases such as programming, while outside of these use cases they would represent their original typographic symbols: The original vertical bar encoded at 0x7C in the original May 12, 1966 draft was then broken as , so it could not be confused with the unbroken logical OR. In the 1967 revision of ASCII, along with the equivalent ISO 464 code published the same year, the code point was defined to be a broken vertical bar, and the exclamation mark character was allowed to be rendered as a solid vertical bar. However, the 1977 revision (ANSI X.3-1977) undid the changes made in the 1967 revision, enforcing that the circumflex could no longer be stylised as a logical NOT symbol, the exclamation mark likewise no longer allowing stylisation as a vertical bar, and defining the code point originally set to the broken bar as a solid vertical bar instead; the same changes were also reverted in ISO 646-1973 published four years prior. Some variants of
EBCDIC Extended Binary Coded Decimal Interchange Code (EBCDIC; ) is an eight-bit character encoding used mainly on IBM mainframe and IBM midrange computer operating systems. It descended from the code used with punched cards and the corresponding six ...
included both versions of the character as different code points. The broad implementation of the
extended ASCII Extended ASCII is a repertoire of character encodings that include (most of) the original 96 ASCII character set, plus up to 128 additional characters. There is no formal definition of "extended ASCII", and even use of the term is sometimes critic ...
ISO/IEC 8859 series in the 1990s also made a distinction between the two forms. This was preserved in Unicode as a separate character at U+00A6 BROKEN BAR (the term "parted rule" is used sometimes in Unicode documentation). Some fonts draw the characters the same (both are solid vertical bars, or both are broken vertical bars). The broken bar does not appear to have any clearly identified uses distinct from those of the vertical bar. In non-computing use — for example in mathematics, physics and general typography — the broken bar is not an acceptable substitute for the vertical bar. US International keyboard showing broken bar on the keycap, even though typing shift+that key produces the solid vertical bar. Many keyboards with US or US-International layout display the broken bar on a keycap even though the solid vertical bar character is produced in modern operating systems. This includes many German QWERTZ keyboards. This is a legacy of keyboards manufactured during the 1980s and 1990s for
IBM PC compatible IBM PC compatible computers are similar to the original IBM PC, XT, and AT, all from computer giant IBM, that are able to use the same software and expansion cards. Such computers were referred to as PC clones, IBM clones or IBM PC clones. ...
computers featuring the broken bar, as such computers used IBM's 8-bit
Code page 437 Code page 437 (CCSID 437) is the character set of the original IBM PC (personal computer). It is also known as CP437, OEM-US, OEM 437, PC-8, or DOS Latin US. The set includes all printable ASCII characters as well as some accented letters (diacri ...
character set based on ASCII, which continued to display the glyph for the broken bar at codepoint 7C on displays from MDA (1981) to VGA (1987) despite the changes made to ASCII in 1977. The broken bar character can be typed (depending on the layout) as or or on Windows and on Linux. It can be inserted into HTML as In some dictionaries, the broken bar is used to mark stress that may be either primary or secondary. That is, covers the pronunciations and .For example, .

## Unicode code points

These glyphs are encoded in Unicode as follows: * (single vertical line) * (single broken line) * (double vertical line ( $\,$ ): used in pairs to indicate
norm Naturally occurring radioactive materials (NORM) and technologically enhanced naturally occurring radioactive materials (TENORM) consist of materials, usually industrial wastes or by-products enriched with radioactive elements found in the envir ...
) * ( Fullwidth form) * * * * * (and various other box drawing characters in the range U+2500 to U+257F) * *