Vertical bar

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"｜" redirects here. For the use of a similar-looking character in vertical Japanese writing, see Chōonpu.
" ‖ " redirects here. For the use of a similar-looking character in African languages, see lateral clicks. For the parallelism symbol see parallel (geometry) and parallel (operator).
Not to be confused with dental click.
|
Vertical bar
In UnicodeU+007C | VERTICAL LINE (|, |, |)
Related
See alsoU+00A6 ¦ BROKEN BAR (¦)

U+2016 ‖ DOUBLE VERTICAL LINE (‖, ‖)

U+2223 ∣ DIVIDES

The vertical bar, |, is a glyph with various uses in mathematics, computing, and typography. It has many names, often related to particular meanings: Sheffer stroke (in logic), pipe, bar, or (literally the word "or"), vbar, and others.[1]

Usage

jsut use shift and the \

Music scoring

Main article: Sheet music

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.[citation needed] 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).[citation needed]

Encoding

Solid vertical bar versus broken bar

The code point 124 (7C hexadecimal) is occupied by a broken bar in a dot matrix printer of the late 1980s, which apparently lacks a solid vertical bar. See the full picture.

Many early video terminals and dot-matrix printers rendered the vertical bar character as the allograph broken bar ¦. This may have been to distinguish the character from the lower-case 'L' and the upper-case 'I' 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 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 symbol.[2] 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.[2] This draft received opposition from the IBM user group SHARE, with its chairman, H. W. Nelson, writing a letter to the American Standards Association 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 universally on all platforms.[3] As a compromise, a requirement was introduced where the exclamation mark (!) and circumflex (^) 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:

It may be desirable to employ distinctive styling to facilitate their use for specific purposes as, for example, to stylize the graphics in code positions 2/1 and 5/14 to those frequently associated with logical OR (|) and logical NOT (¬) respectively.

— X3.2 document X3.2/475[4]

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.[5][6] 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;[5] the same changes were also reverted in ISO 646-1973 published four years prior.

Some variants of EBCDIC included both versions of the character as different code points. The broad implementation of the extended ASCII 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).[7][failed verification] The broken bar does not appear to have any clearly identified uses distinct from those of the vertical bar.[8] 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 pressing ⇧ Shift+\ produces the solid vertical bar.
Full character set of IBM's Code page 437 rendered in VGA, which displays the broken bar glyph for codepoint 7C, despite the 1977 revision to ASCII

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 computers featuring the broken bar, as such computers used IBM's 8-bit Code page 437 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 UK/Ireland keyboard has both symbols engraved: the broken bar is given as an alternate graphic on the "grave" (backtick) key; the solid bar is on the backslash key.

The broken bar character can be typed (depending on the layout) as AltGr+` or AltGr+6 or AltGr+⇧ Shift+Right \ on Windows and Compose!^ 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, [¦ba] covers the pronunciations [ˈba] and [ˌba].[9]

Unicode code points

These glyphs are encoded in Unicode as follows:

Code pages and other historical encodings

Code pages, ASCII, ISO/IEC, EBCDIC, Shift-JIS, etc.       Vertical bar (|) Broken bar (¦)
ASCII,
CP437, CP667, CP720, CP737, CP790, CP819, CP852, CP855, CP860, CP861, CP862, CP865, CP866, CP867, CP869, CP872, CP895, CP932, CP991 		124 (7Ch) none
CP775 167 (A7h)
CP850, CP857, CP858 221 (DDh)
CP863 160 (A0h)
CP864 219 (DBh)
ISO/IEC 8859-1, -7, -8, -9, -13,
CP1250, CP1251, CP1252, CP1253, CP1254, CP1255, CP1256, CP1257, CP1258 		166 (A6h)
ISO/IEC 8859-2, -3, -4, -5, -6, -10, -11, -14, -15, -16 none
EBCDIC CCSID 37 79 (4Fh) 106 (6Ah)
EBCDIC CCSID 500 187 (BBh)
JIS X 0208, JIS X 0213 Men-ku-ten 1-01-35 (7-bit: 2143h; Shift JIS: 8162h; EUC: A1C3h)[a] none


See also

Look up vertical bar in Wiktionary, the free dictionary.

Notes

  1. ^ The Shift JIS and EUC encoded forms also include the ASCII vertical bar in its usual encoding (see halfwidth and fullwidth forms). The same applies when the 7-bit form is used as part of ISO-2022-JP (allowing switching to and from ASCII).

References

  1. ^ Raymond, Eric S. "ASCII". The Jargon File. Archived from the original on Oct 30, 2023.
  2. ^ a b Fischer, Eric (2012). The Evolution of Character Codes, 1874-1968 (Thesis). Penn State University. CiteSeerX 10.1.1.96.678. Retrieved July 10, 2020.
  3. ^ H. W. Nelson, letter to Thomas B. Steel, June 8, 1966, Honeywell Inc. X3.2 Standards Subcommittee Records, 1961-1969 (CBI 67), Charles Babbage Institute, University of Minnesota, Minneapolis, box 1, folder 23.
  4. ^ X3.2 document X3.2/475, December 13, 1966, Honeywell Inc. X3.2 Standards Subcommittee Records, 1961-1969 (CBI 67), Charles Babbage Institute, University of Minnesota, Minneapolis, box 1, folder 22.
  5. ^ a b Salste, Tuomas (January 2016). "7-bit character sets: Revisions of ASCII". Aivosto Oy. urn:nbn:fi-fe201201011004. Archived from the original on 2016-06-13. Retrieved 2016-06-13.
  6. ^ Korpela, Jukka. "Character histories - notes on some Ascii code positions". Archived from the original on 2020-03-11. Retrieved 2020-05-31.
  7. ^ Jim Price (2010-05-24). "ASCII Chart: IBM PC Extended ASCII Display Characters". Retrieved 2012-02-23.
  8. ^ Jukka "Yucca" Korpela (2006-09-20). "Detailed descriptions of the characters". Retrieved 2012-02-23.
  9. ^ For example, "Balearic". Merriam-Webster.com Dictionary..
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