The percent sign % (sometimes per cent sign in British English) is the symbol used to indicate a percentage, a number or ratio as a fraction of 100. Related signs include the permille (per thousand) sign and the permyriad (per ten thousand) sign (also known as a basis point), which indicate that a number is divided by one thousand or ten thousand, respectively. Higher proportions use parts-per notation.

%
Percent sign
In UnicodeU+0025 % PERCENT SIGN (%)
Different from
Different fromU+2052 COMMERCIAL MINUS SIGN
U+00F7 ÷ DIVISION SIGN
Related
See alsoU+2030 PER MILLE SIGN
U+2031 PER TEN THOUSAND SIGN (Basis point)

Correct style edit

Form and spacing edit

English style guides prescribe writing the percent sign following the number without any space between (e.g. 50%).[sources 1] However, the International System of Units and ISO 31-0 standard prescribe a space between the number and percent sign,[8][9][10] in line with the general practice of using a non-breaking space between a numerical value and its corresponding unit of measurement.

Other languages have other rules for spacing in front of the percent sign:

  • In Czech and in Slovak, the percent sign is spaced with a non-breaking space if the number is used as a noun.[11] In Czech, no space is inserted if the number is used as an adjective (e.g. “a 50% increase”),[12] whereas Slovak uses a non-breaking space in this case as well.[13]
  • In Finnish, the percent sign is always spaced, and a case suffix can be attached to it using the colon (e.g. 50 %:n kasvu 'an increase of 50%').[14]
  • In French, the percent sign must be spaced with a non-breaking space.[15][16]
  • According to the Real Academia Española, in Spanish, the percent sign should be spaced now, despite the fact that it is not the linguistic norm.[17] Despite that, in North American Spanish (Mexico and the US), several style guides and institutions either recommend the percent sign be written following the number without any space between or do so in their own publications in accordance with common usage in that region.[18][19]
  • In Russian, the percent sign is rarely spaced, contrary to the guidelines of the GOST 8.417-2002 state standard.
  • In Chinese, the percent sign is almost never spaced, probably because Chinese does not use spaces to separate characters or words at all.[citation needed]
  • According to the Swedish Language Council, the percent sign should be preceded by a space in Swedish, as all other units.
  • In German, the space is prescribed by the regulatory body in the national standard DIN 5008.
  • In Turkish and some other Turkic languages, the percent sign precedes rather than follows the number, without an intervening space.
  • In Persian texts, the percent sign may either precede or follow the number, in either case without a space.
  • In Arabic, the percent sign follows the number; as Arabic is written from right to left, this means that the percent sign is to the left of the number, usually without a space.
  • In Hebrew, the percent sign is written to the right of the number, just as in English, without an intervening space. This is because numbers in Hebrew (which otherwise is written from right to left) are written from left to right, as in English.
  • In Dutch, the official rule (NBN Z 01-002) is to place a space between the number and the sign (e.g. "een stijging van 50 %"), but most of the time, the space is missing (e.g. "een stijging van 50%").[20]

Usage in text edit

It is often recommended that the percent sign only be used in tables and other places with space restrictions. In running text, it should be spelled out as percent or per cent (often in newspapers). For example, not "Sales increased by 24% over 2006" but "Sales increased by 24 percent over 2006".[21][22][23]

Evolution edit

Prior to 1425, there is no known evidence of a special symbol being used for percentage. The Italian term per cento, "for a hundred", was used as well as several different abbreviations (e.g. "per 100", "p 100", "p cento", etc.). Examples of this can be seen in the 1339 arithmetic text (author unknown) depicted below.[24] The letter p with its descender crossed by a horizontal or diagonal strike (to indicate abbreviation) conventionally stood for per, por, par, or pur in Medieval and Renaissance palaeography.[25]

 
1339 arithmetic text in Rara Arithmetica, p. 437

At some point, a scribe used the abbreviation "pc" with a tiny loop or circle (depicting the ending -o used in Italian ordinals, as in primo, secondo, etc.; it is analogous to the English "-th" as in "25th"). This appears in some additional pages of a 1425 text which were probably added around 1435.[26] This is shown below (source, Rara Arithmetica p. 440).

 
1425 arithmetic text in Rara Arithmetica, p. 440

The "pc" with a loop eventually evolved into a horizontal fraction sign by 1650 (see below for an example in a 1684 text[27]) and thereafter lost the "per".[28]

 
1684 arithmetic text in Rara Arithmetica, p. 441

In 1925, D. E. Smith wrote, "The solidus form ( ) is modern."[29]

Usage edit

Encodings edit

Unicode edit

The Unicode code points are:

ASCII edit

The ASCII code for the percent character is 37, or 0x25 in hexadecimal.

In computers edit

Names for the percent sign include percent sign (in ITU-T), mod, grapes (in hacker jargon)[citation needed], and the humorous double-oh-seven (in INTERCAL).

In computing, the percent character is also used for the modulo operation in programming languages that derive their syntax from the C programming language, which in turn acquired this usage from the earlier B.[31]

In the textual representation of URIs, a % immediately followed by a 2-digit hexadecimal number denotes an octet specifying (part of) a character that might otherwise not be allowed in URIs (see percent-encoding).

In SQL, the percent sign is a wildcard character in "LIKE" expressions, for example SELECT * FROM table WHERE fullname LIKE 'Lisa %' will fetch all records whose names start with "Lisa ".

In TeX (and therefore also in LaTeX) and PostScript, and in GNU Octave and MATLAB,[32] a % denotes a line comment.

In BASIC, Visual Basic, ASP, and VBA a trailing % after a variable name marks it as an integer.

In ASP, the percent sign can be used to indicate the start and end of the ASP code <%...... %>

In Perl % is the sigil for hashes.

In many programming languages' string formatting operations (performed by functions such as printf and scanf), the percent sign denotes parts of the template string that will be replaced with arguments. (See printf format string.) In Python and Ruby the percent sign is also used as the string formatting operator.[33][34][35]

In the command processors COMMAND.COM (DOS) and CMD.EXE (OS/2 and Windows), %1, %2,... stand for the first, second,... parameters of a batch file. %0 stands for the specification of the batch file itself as typed on the command line. The % sign is also used similarly in the FOR command. %VAR1% represents the value of an environment variable named VAR1. Thus: set PATH=c:\;%PATH% sets a new value for PATH, that being the old value preceded by "c:\;". Because these uses give the percent sign special meaning, the sequence %% (two percent signs) is used to represent a literal percent sign, so that: set PATH=c:\;%%PATH%% would set PATH to the literal value "c:\;%PATH%".

In the C Shell, % is part of the default command prompt.

In linguistics edit

In linguistics, the percent sign is prepended to an example sentence or other string to show that it is judged well-formed (grammatical) by some speakers and ill-formed by others. This may be due to differences in dialect or even individual idiolects.[36][37] This use is similar to those of the asterisk to mark ill-formed strings, the question mark to mark strings where well-formedness is unclear, and the number sign to mark strings that are syntactically well-formed but semantically or pragmatically nonsensical.

See also edit

Reference notes edit

Notes edit

  1. ^ "Guardian and Observer style guide: P". The Guardian. 30 April 2021. Archived from the original on 28 December 2019. Retrieved 16 March 2023.
  2. ^ "The Chicago Manual of Style". University of Chicago Press. 2003. Archived from the original on 5 January 2009. Retrieved 5 January 2007.
  3. ^ Publication Manual of the American Psychological Association. 1994. Washington, DC: American Psychological Association, p. 114.
  4. ^ Merriam-Webster's Manual for Writers and Editors. 1998. Springfield, MA: Merriam-Webster, p. 128.
  5. ^ Jenkins, Jana et al. 2011. The IBM Style Guide: Conventions for Writers and Editors. Boston, MA: Pearson Education, p. 162.
  6. ^ Covey, Stephen R. FranklinCovey Style Guide: For Business and Technical Communication. Salt Lake City, UT: FranklinCovey, p. 287.
  7. ^ Dodd, Janet S. 1997. The ACS Style Guide: A Manual for Authors and Editors. Washington, DC: American Chemical Society, p. 264.
  8. ^ "SI Brochure". International Bureau of Weights and Measures. 2006. Archived from the original on 21 March 2019. Retrieved 5 May 2016.
  9. ^ "The International System of Units" (PDF). International Bureau of Weights and Measures. 2006. Archived (PDF) from the original on 13 March 2020. Retrieved 6 August 2007.
  10. ^ "Quantities and units – Part 0: General principles". International Organization for Standardization. 22 December 1999. Archived from the original on 29 May 2007. Retrieved 5 January 2007.
  11. ^ "Internetová jazyková příručka". Ústav pro jazyk český Akademie věd ČR. 2014. Archived from the original on 14 February 2015. Retrieved 24 November 2014.
  12. ^ "Jazyková poradna ÚJČ AV ČR: FAQ". Ústav pro jazyk český Akademie věd ČR. 2002. Archived from the original on 19 April 2002. Retrieved 16 March 2009.
  13. ^ "Jazyková poradňa". Petit Press, a.s. 2013. Archived from the original on 21 February 2009. Retrieved 26 October 2019.
  14. ^ "Kielikello 2/2006". kotus.fi. Kotimaisten kielten keskus. 2006. Archived from the original on 1 May 2015. Retrieved 30 June 2015.
  15. ^ Guide des principales règles typographiques (PDF). Université Joseph-Fourier. Archived (PDF) from the original on 3 March 2016. Retrieved 8 June 2022.
  16. ^ André, Jacques. Petites leçons de typographie (PDF). Rennes: Institut de recherche en informatique et systèmes aléatoires. p. 34. Archived (PDF) from the original on 20 January 2011. Retrieved 8 June 2022.
  17. ^ "El % se escribe separado de la cifra a la que acompaña". fundeu.es. Fundeu. 2012. Archived from the original on 24 November 2021. Retrieved 24 November 2021.
  18. ^ "Normas particulares de estilo". colmex.mx. Colegio de México. 2020. Archived from the original on 10 May 2022. Retrieved 5 April 2022.
  19. ^ "¿En un texto, es correcto usar el signo de porcentaje o tiene que escribirse por ciento?". academia.org.mx. Academia Mexicana de la Lengua. 2020. Archived from the original on 6 February 2023. Retrieved 5 April 2022.
  20. ^ "procentteken (spatie)". www.vlaanderen.be (in Dutch). Archived from the original on 27 November 2021. Retrieved 27 November 2021.
  21. ^ American Economic Review: Style Guide Archived 2007-12-25 at the Wayback Machine
  22. ^ "UNC Pharmacy style guide". Archived from the original on 12 June 2007. Retrieved 16 October 2007.
  23. ^ "University of Colorado style guide". Archived from the original on 2 November 2007. Retrieved 16 October 2007.
  24. ^ Smith 1898, p. 437
  25. ^ Letter p. Archived 18 April 2009 at the Wayback Machine / Cappelli, Adriano: Lexicon Abbreviaturarum Archived 8 May 2015 at the Wayback Machine. 2. verb. Aufl. Leipzig 1928. Wörterbuch der Abkürzungen: P. pages 256–257
  26. ^ Smith 1898, pp. 439-440
  27. ^ Smith 1898, p. 441
  28. ^ Smith 1898, p. 440
  29. ^ Smith 1925, Vol. 2, p. 250 in Dover reprint of 1958, ISBN 0-486-20430-8
  30. ^ HTML5 is the only version of HTML that has a named entity for the percent sign, see https://www.w3.org/TR/html4/sgml/entities.html Archived 1 April 2018 at the Wayback Machine ("The following sections present the complete lists of character entity references.") and https://www.w3.org/TR/2014/CR-html5-20140731/syntax.html#named-character-references Archived 5 August 2017 at the Wayback Machine ("percnt;").
  31. ^ Thompson, Ken (1996). "Users' Reference to B". Archived from the original on 6 July 2006.
  32. ^ "2.7.1 Single Line Comments". GNU. Archived from the original on 20 July 2018. Retrieved 20 July 2018.
  33. ^ "Python 2 – String Formatting Operations". Archived from the original on 4 November 2015. Retrieved 28 October 2015.
  34. ^ "Python 3 – printf-style String Formatting". Archived from the original on 14 June 2020. Retrieved 28 October 2015.
  35. ^ "Ruby – String#%". Archived from the original on 8 October 2011. Retrieved 28 October 2015.
  36. ^ Trask, R. L. (1993). A Dictionary of Grammatical Terms in Linguistics. London: Routledge. p. 203. ISBN 0-415-08627-2.
  37. ^ Crystal, David (2008). A Dictionary of Linguistics and Phonetics (6th ed.). Cambridge: Cambridge University Press. p. 355. ISBN 978-1-4051-5296-9.

References edit