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{{Short description|Comma before the conjunction in a list}}
{{redirect|Oxford Comma|the song|Oxford Comma (song)}}
{{Use mdy dates|date=February 2023}}

The '''serial comma''' (also referred to as the '''series comma''', '''Oxford comma''',<ref>{{cite book | year = 2016 |first1=Bryan A. |last1=Garner| authorlink = Bryan A. Garner | title = Garner's Modern English Usage | publisher = [[Oxford University Press]] | page = 748 | isbn = 978-0-19-049148-2}}</ref> or '''Harvard comma'''<ref>{{Cite web|url=https://writersmentor.com/oxford-comma-necessary-serial-comma-harvard-comma/|title=Serial comma - Oxford comma - Harvard comma|last=Upadhyay|first=Abhishek|website=Writers' Mentor|access-date=January 15, 2019|archive-date=January 16, 2019|archive-url=https://web.archive.org/web/20190116041247/https://writersmentor.com/oxford-comma-necessary-serial-comma-harvard-comma/|url-status=dead}}</ref>) is a [[comma]] placed after the second-to-last term in a list (just before the [[coordinating conjunction|conjunction]]) when writing out three or more terms.<ref>The terms ''Oxford comma'' and ''Harvard comma'' come from [[Oxford University Press]] and [[Harvard University Press]], where serial-comma use is the [[Style guide|house style]].</ref><ref>Sometimes, the term also denotes the comma that might come before ''etc.'' at the end of a list (''see'' the Australian Government Publishing Service's ''Style Manual for Authors, Editors, and Printers'', below). Such an extension is reasonable, since ''etc.'' is the abbreviation of the Latin phrase {{lang|la|et cetera}} ({{lit|and other things}}).</ref><ref>The ''serial comma'' sometimes refers to ''any'' of the separator commas in a list, but this is a rare, old-fashioned usage. Herein, the term is used only as defined above.</ref> For example, a list of three countries might be punctuated with the serial comma as "France, Italy, and Spain" or without it as "France, Italy and Spain". The serial comma can help avoid ambiguity in some situations, but can also create it in others.<ref name=":0" /> There is no universally accepted standard for its use.<ref>{{Cite web |last=McArthur |first=Tom |date=1998 |title=Comma |url=https://www.encyclopedia.com/humanities/encyclopedias-almanacs-transcripts-and-maps/comma |access-date=2024-03-18 |website=Encyclopedia.com |series=Concise Oxford Companion to the English Language |archive-date=August 31, 2024 |archive-url=https://web.archive.org/web/20240831005743/https://www.encyclopedia.com/literature-and-arts/language-linguistics-and-literary-terms/language-and-linguistics/comma#COMMA |url-status=live }}</ref>

The serial comma is popular in [[Literary language|formal writing]] (such as in [[Academic writing|academic]], [[Literary language|literary]], and [[Legal writing|legal]] contexts)<ref name="Gramlich" /><ref name=":2" /> but is usually omitted in [[journalism]] as a way to save space.<ref name=":2" /><ref name=":4" /><ref name="BusInsider" /> Its popularity in informal and semi-formal writing depends on the [[List of dialects of English|variety of English]]; it is usually excluded in [[British English]], while in [[American English]] it is common and often considered mandatory outside journalism.<ref name=":5" /><ref name=":3">''The Oxford Style Manual'', 2002: "The presence or lack of a comma before ''and'' or ''or'' ... has become the subject of much spirited debate. For a century it has been part of OUP style ..., to the extent that the convention has come to be called the 'Oxford comma'. But it is commonly used by many other publishers here and abroad, and forms a routine part of style in US and Canadian English" (p. 121).</ref><ref name="shoots">{{cite book|title= Eats, Shoots & Leaves: The Zero Tolerance Approach to Punctuation|url= https://archive.org/details/eatsshootsleave00trus|url-access= limited|last= Truss|first= Lynn |year= 2004|publisher=[[Gotham Books]]|location= New York|isbn= 1-59240-087-6|page=[https://archive.org/details/eatsshootsleave00trus/page/84 84]}}</ref> Academic and legal [[Style guide|style guides]] such as the [[APA style]],<ref>{{cite web |author=David Becker |title=Using Serial Commas |url=http://blog.apastyle.org/apastyle/2011/04/using-serial-commas.html |url-status=live |archive-url=https://web.archive.org/web/20141019015746/http://blog.apastyle.org/apastyle/2011/04/using-serial-commas.html |archive-date=October 19, 2014 |access-date=October 14, 2014 |publisher=[[American Psychological Association|APA]]}}</ref> ''[[The Chicago Manual of Style]]'', ''[[Garner's Modern American Usage]]'',<ref name="Garner32">{{cite book |last1=Garner |first1=Bryan A. |author-link1=Bryan A. Garner |title=Garner's Modern American Usage |date=2009 |publisher=Oxford University Press |isbn=978-0-19-538275-4 |edition=3rd |page=676 |quote=... omitting the final comma may cause ambiguities, whereas including it never will ...}}</ref> [[William Strunk Jr.|Strunk]] and [[E. B. White|White]]'s ''[[The Elements of Style]]'',<ref name="Strunk & White">{{cite book |last1=Strunk |first1=William Jr. |url=https://books.google.com/books?id=pYYUAQAAIAAJ&q=In+a+series+of+three+or+more |title=The Elements of Style |last2=White |first2=E. B. |publisher=Penguin Press |others=Illustrated by Maira Kalman |year=2005 |isbn=9-7815-9420-069-4 |edition=Illustrated |page=3 |quote=In a series of three or more terms with a single conjunction, use a comma after each term except the last.}}</ref> and the ''[[U.S. Government Printing Office]] Style Manual''<ref>{{cite web |date=2016 |title=GPO Style Manual |url=https://www.govinfo.gov/content/pkg/GPO-STYLEMANUAL-2016/pdf/GPO-STYLEMANUAL-2016.pdf |url-status=live |archive-url=https://web.archive.org/web/20180729022842/https://www.govinfo.gov/content/pkg/GPO-STYLEMANUAL-2016/pdf/GPO-STYLEMANUAL-2016.pdf |archive-date=July 29, 2018 |access-date=January 10, 2023 |publisher=United States Government Publishing Office |pages=201–202 |quote=The comma is used ... after each member within a series of three or more words, phrases, letters, or figures used with ''and'', ''or'', or ''nor''.}}</ref> either recommend or require the serial comma, as does ''[[The Oxford Style Manual]]'' (hence the alternative name "Oxford comma").<ref name=":3" /> Newspaper stylebooks such as the ''[[Associated Press Stylebook]]'', ''The New York Times Style Book,''<ref>{{Cite book|url=https://archive.org/details/newyorktimesstyl00newy/page/30/mode/2up|author=Jordan Lewis|title=The New York Times Style Book for Writers and Editors|publisher=[[McGraw Hill]]|year=1962}}</ref> and [[The Canadian Press]] stylebook typically recommend against it. Most British style guides do not require it, with ''[[The Economist]] Style Guide'' noting most British writers use it only to avoid ambiguity.<ref name=":5">{{cite book|title=The Economist Style Guide|publisher=Profile Books|year=2012|isbn=978-1-84668-606-1|edition=10th|pages=152–153|quote=Most American writers and publishers use the serial comma; most British writers and publishers use the serial comma only when necessary to avoid ambiguity ...}}</ref> 

While many sources provide default recommendations on whether to use the serial comma as a matter of course, most also include exceptions for situations where it is necessary to avoid ambiguity (see {{Section link|2=Recommendations by style guides}}).<ref>{{cite web|title=University of Oxford Style Guide|url=https://www.ox.ac.uk/sites/files/oxford/media_wysiwyg/University%20of%20Oxford%20Style%20Guide.pdf|page=13|quote=Note that there is no comma between the penultimate item in a list and 'and'/'or', unless required to prevent ambiguity – this is sometimes referred to as the 'Oxford comma'.|access-date=June 17, 2021|archive-date=October 9, 2022|archive-url=https://ghostarchive.org/archive/20221009/https://www.ox.ac.uk/sites/files/oxford/media_wysiwyg/University%20of%20Oxford%20Style%20Guide.pdf|url-status=live}}</ref>

==History==
The comma itself is widely attributed to [[Aldus Manutius]], a 15th-century Italian printer who used a mark—now recognized as a comma—to separate words.<ref>{{Cite web |last=Nadeau |first=Barbie Latza |title=The Man Who Changed Reading Forever |url=https://www.smithsonianmag.com/travel/aldus-manutius-printing-typeface-typography-italics-venice-180956855/ |date=6 November 2015 |access-date=2023-07-25 |website=[[Smithsonian Magazine]] |language=en |archive-date=July 29, 2023 |archive-url=https://web.archive.org/web/20230729050628/https://www.smithsonianmag.com/travel/aldus-manutius-printing-typeface-typography-italics-venice-180956855/ |url-status=live }}</ref> Etymologically, the word ''comma'', which became widely used to describe Manutius's mark, comes from the Greek {{Lang|grc|κόμμα}} ({{Lit|to cut off}}).<ref>{{Cite web |last=pidgin |first=the inquisitive |date=2018-06-15 |title=From Where Did We Get the Comma? |url=https://medium.com/@jonhudson.main/from-where-did-we-get-the-comma-d15fcd9839bb |access-date=2024-03-18 |website=Medium |language=en |archive-date=August 31, 2024 |archive-url=https://web.archive.org/web/20240831005831/https://medium.com/@jonhudson.main/from-where-did-we-get-the-comma-d15fcd9839bb |url-status=live }}</ref> The serial comma has been used for centuries in a variety of languages, though not necessarily in a uniform or regulated manner.<ref>{{Cite journal |last1=Calle-Martín |first1=Javier |last2=Criado-Peña |first2=Miriam |date=2022-04-03 |title='A very pleasant, safe, and effectual medicine': The serial comma in the history of English |url=https://www.tandfonline.com/doi/full/10.1080/07268602.2022.2123700 |journal=Australian Journal of Linguistics |language=en |volume=42 |issue=2 |pages=165–183 |doi=10.1080/07268602.2022.2123700 |issn=0726-8602 |hdl=10630/29636 |hdl-access=free |access-date=July 25, 2023 |archive-date=August 31, 2024 |archive-url=https://web.archive.org/web/20240831005743/https://www.tandfonline.com/doi/full/10.1080/07268602.2022.2123700 |url-status=live }}</ref> 

The serial comma is most often attributed to [[Horace Hart]], the printer and controller of the [[Oxford University Press]] from 1893 to 1915. Hart wrote the eponymous ''[[Hart's Rules for Compositors and Readers]]'' in 1905 as a style guide for the employees working at the press.<ref>{{Cite web |title= Horace Hart {{!}} Artist |publisher= Royal Academy of Arts |url= https://www.royalacademy.org.uk/art-artists/name/horace-hart |access-date= 2023-07-25 |website= royalacademy.org.uk |archive-date= July 25, 2023 |archive-url= https://web.archive.org/web/20230725160308/https://www.royalacademy.org.uk/art-artists/name/horace-hart |url-status= live }}</ref> The guide called for the use of the serial comma,<ref>{{Cite book |first=Horace |last=Hart |author-link=Horace Hart |url=https://books.google.com/books?id=6avlAAAAMAAJ |title=Hart's Rules for Compositors and Readers at the University Press, Oxford |date=1983 |location=Oxford |publisher=Oxford University Press |isbn=978-0-19-212983-3 |language=en}}</ref> but the punctuation mark had no distinct name until 1978, when Peter Sutcliffe referred to the serial comma as such in his historical account of the Oxford University Press.<ref name=":1">{{Cite book |last=Sutcliffe |first=Peter H. |url=https://books.google.com/books?id=rAUmnk2VNT4C |title=The Oxford University Press: An Informal History |date=1978 |location=Oxford |publisher=Clarendon Press |isbn=978-0-19-951084-9 |language=en}}</ref>

Sutcliffe, however, attributed the serial comma not to Horace Hart but to [[F. Howard Collins]],<ref name=":1" /> who mentioned it in his 1905 book, ''Author & Printer: A Guide for Authors, Editors, Printers, Correctors of the Press, Compositors, and Typists''.<ref>{{Cite book |last=Collins |first=Frederick Howard |url=https://books.google.com/books?id=CdQWAAAAIAAJ |title=Author & Printer: A Guide for Authors, Editors, Printers, Correctors of the Press, Compositors and Typists |date=1905 |publisher=H. Frowde |language=en}}</ref>

==Arguments for and against==
Common arguments ''for'' the consistent use of the serial comma are:
*The comma's use is consistent with the conventional practice of the region.<ref>''The Oxford Style Manual'', 2002: "But it is commonly used by many other publishers here and abroad, and forms a routine part of style in US and Canadian English" (p. 121).</ref>
*It can resolve [[Syntactic ambiguity|ambiguity]] (see [[#Ambiguity|examples below]]).<ref>''The Oxford Style Manual'', 2002; from discussion of the serial comma: "The last comma serves also to resolve ambiguity, particularly when any of the items are compound terms joined by a conjunction" (p. 122).</ref><ref name=Petelin/><ref name=USHouse>U.S. House Legislative Counsel's Manual on Drafting Style, No. HLC 104-1, § 351 at 58 (1995)</ref>
*{{anchor|Semicolon}}Its use is consistent with other means of separating items in a list (for example, when [[semicolon]]s are used to separate items, one is always included before the last item).<ref>''The Oxford Style Manual'', 2002; in discussion of the semicolon, examples are given in which complex listed items are separated by semicolons, with the same structure and on the same principles as are consistently recommended for use of the comma as a list separator in the preceding section (pp. 124–5)</ref>

Common arguments ''against'' the consistent use of the serial comma are:
*The comma's omission is consistent with the conventional practice of the region.<ref>Ridout, R., and Witting, C., ''The Facts of English'', Pan, 1973, p. 79: "Usually in such lists 'and' is not preceded by a comma, […]".</ref>
*It can introduce ambiguity.
*When space is at a premium, it adds redundancy and unnecessary bulk to the text.

Many sources are against both systematic use and systematic avoidance of the serial comma, making recommendations in a more nuanced way as reflected in [[#Recommendations by style guides|recommendations by style guides]].

==Ambiguity==
{{Further|Syntactic ambiguity}}
Omitting the serial comma may create ambiguity; writers who normally avoid the comma often use one to avoid this. Consider the [[wikt:apocryphal|apocryphal]] book dedication below:<ref>Based on example quoted in {{cite news|url=https://www.nytimes.com/2017/03/16/us/oxford-comma-lawsuit.html?_r=0|last=Victor|first=Daniel|title=Lack of Oxford Comma Could Cost Maine Company Millions in Overtime Dispute|newspaper=[[The New York Times]]|date=March 16, 2017|access-date=March 17, 2017|archive-date=March 17, 2017|archive-url=https://web.archive.org/web/20170317092502/https://www.nytimes.com/2017/03/16/us/oxford-comma-lawsuit.html?_r=0|url-status=live}}</ref>
:''To my parents, Mother Teresa and the pope.''
There is ambiguity about the writer's parentage as "Mother Teresa and the pope" can be read as an [[appositive phrase]] renaming of<ref>{{cite journal |last1=Emonds |first1=Joseph |title=Appositive Relatives Have No Properties |journal=Linguistic Inquiry |date=1979 |volume=10 |issue=2 |pages=211–243 |jstor=4178107 }}</ref> ''my parents'', leading the reader to believe that the writer claims that [[Mother Teresa]] and [[Pope|the pope]] are their parents. A comma before the ''and'' removes the ambiguity:
:''To my parents, Mother Teresa, and the pope.''
Nevertheless, lists can also be written in other ways that eliminate the ambiguity without introducing the serial comma, such as by changing the word order, or by using other or no punctuation to introduce or delimit them (though the emphasis may thereby be changed):
:''To the pope, Mother Teresa and my parents.''

An example collected by [[Patrick Nielsen Hayden|Nielsen Hayden]] was found in a newspaper account of a documentary about [[Merle Haggard]]:
:''Among those interviewed were his two ex-wives, [[Kris Kristofferson]] and [[Robert Duvall]].''<ref>{{cite web |url=http://nielsenhayden.com/makinglight/archives/012652.html |title=Making Light |publisher=Nielsenhayden.com |date=October 21, 2010 |access-date=February 10, 2013 |archive-date=January 22, 2013 |archive-url=https://web.archive.org/web/20130122013013/http://nielsenhayden.com/makinglight/archives/012652.html |url-status=live }}</ref>
A serial comma following "Kris Kristofferson" would help prevent this being understood as Kris Kristofferson and Robert Duvall being the ex-wives in question.

In some circumstances, using the serial comma can create ambiguity. If the book dedication above is changed to
:''To my mother, Mother Teresa, and the pope.''
the comma after ''Mother Teresa'' creates ambiguity because it can be read as an appositive phrase implying that the writer's mother is Mother Teresa. This leaves it unclear whether this is a list of three entities (1, my mother; 2, Mother Teresa; and 3, the pope) or of only two entities (1, my mother, who is Mother Teresa; and 2, the pope).<ref name=":0">{{Cite book|last=Adams|first=Kenneth A.|title=A Manual of Style for Contract Drafting|edition=3rd|publisher=American Bar Association|date=2013|at=12.61|isbn=978-1-61438-803-6}}</ref>

Also:
:''They went to [[Oregon]] with Betty, a maid, and a cook.''
This is ambiguous because it is unclear whether "a maid" is an [[appositive]] renaming of Betty or the second in a list of three people. On the other hand, removing the final comma:
:''They went to Oregon with Betty, a maid and a cook.''
leaves the possibility that Betty is both a maid and a cook (with "a maid and a cook" read as an appositive phrase).<ref>{{cite journal |last1=Delorme |first1=Evelyne |last2=Dougherty |first2=Ray C. |date=1972 |title=Appositive NP Constructions: We, the Men; We Men; I, a Man; Etc. |journal=Foundations of Language |volume=8 |issue=1 |pages=2–29 |jstor=25000571}}</ref> In this case, neither the serial-comma style—nor the no-serial-comma style—resolves the ambiguity. A writer who intends a list of three distinct people (Betty, maid, cook) may create an ambiguous sentence, regardless of whether the serial comma is adopted. Furthermore, if the reader is unaware of which convention is being used, both styles can be ambiguous in cases such as this.

These forms (among others) would remove the ambiguity:
* One person
** ''They went to Oregon with Betty, who was a maid and a cook.''
** ''They went to Oregon with Betty, both a maid and a cook.''
** ''They went to Oregon with Betty (a maid and cook).''
** ''They went to Oregon with Betty, their maid and cook.''
* Two people
** ''They went to Oregon with Betty (a maid) and a cook.''
** ''They went to Oregon with Betty—a maid—and a cook.''
** ''They went to Oregon with Betty, a maid, and with a cook.''
** ''They went to Oregon with the maid Betty and a cook.''
** ''They went to Oregon with a cook and Betty, a maid.''
* Three people
** ''They went to Oregon with Betty, as well as a maid and a cook.''
** ''They went to Oregon with Betty and a maid and a cook.''
** ''They went to Oregon with Betty, one maid and a cook.''
** ''They went to Oregon with a maid, a cook, and Betty.''
** ''They went to Oregon with a maid, a cook and Betty.''
** ''They went with Betty to Oregon with a maid and a cook.''

===In general===
* The list '''x, y and z''' is unambiguous if '''y and z''' cannot be read as a renaming of '''x'''.
* Equally, '''x, y, and z''' is unambiguous if '''y''' cannot be read as a renaming of '''x'''.
* If neither '''y''' nor '''y and z''' can be read as a renaming of '''x''', then both forms of the list are unambiguous, but if both '''y''' and '''y and z''' can be read as a renaming of '''x''', then both forms of the list are ambiguous.
* '''x and y and z''' is unambiguous if '''x and y''' and '''y and z''' cannot both be grouped.

Ambiguities can often be resolved by the selective use of semicolons instead of commas when more separation is required.<ref>{{cite journal |id={{ProQuest|237293138}} |last1=Watkins |first1=Ron |title=The Semicolon |journal=English Journal |volume=93 |issue=4 |date=March 2004 |page=22 |doi=10.2307/4128975 |jstor=4128975 }}</ref> General practice across style guides involves using semicolons when individual items have their own punctuation or coordinating conjunctions, but typically a "serial semicolon" is required.<ref>{{cite journal |last1=Bruthiaux |first1=Paul |title=The Rise and Fall of the Semicolon: English Punctuation Theory and English Teaching Practice |journal=Applied Linguistics |date=March 1995 |volume=16 |issue=1 |pages=1–14 |doi=10.1093/applin/16.1.1 }}</ref>

==<span id="Usage"></span><span id="Recommendations by style guides"></span>Recommendations by style guides==

[[Lynne Truss]] writes: "There are people who embrace the Oxford comma, and people who don't, and I'll just say this: ''never'' get between these people when drink has been taken."<ref name="shoots"/>

Omitting a serial comma is often characterized as a journalistic style of writing, as contrasted with a more academic or formal style.<ref name=Gramlich/><ref name=":2">{{cite web |first=Troy |last=Reimink |url=http://www.record-eagle.com/news/local_news/troy-reimink-the-oxford-comma-is-an-abomination-but-it/article_53963e17-3238-5579-a5af-78b833c223fa.html |title=The Oxford comma is an abomination, but it's now the law |newspaper=[[The Traverse City Record-Eagle]] |date=February 16, 2018 |access-date=March 3, 2018 |archive-date=February 16, 2018 |archive-url=https://web.archive.org/web/20180216234223/http://www.record-eagle.com/news/local_news/troy-reimink-the-oxford-comma-is-an-abomination-but-it/article_53963e17-3238-5579-a5af-78b833c223fa.html |url-status=live }}</ref><ref name=BusInsider>{{cite web |first=Gus |last=Lubin |url=http://www.businessinsider.com/do-you-need-the-oxford-comma-2013-9 |title=The Oxford Comma Is Extremely Overrated |work=[[Business Insider]] |date=September 20, 2013 |access-date=March 3, 2018 |archive-date=March 4, 2018 |archive-url=https://web.archive.org/web/20180304054722/http://www.businessinsider.com/do-you-need-the-oxford-comma-2013-9 |url-status=live }}</ref> Journalists typically do not use the comma, possibly for economy of space.<ref name=":4">{{cite book | year = 2003 | author = Bryan A. Garner | title = Garner's Modern American Usage | location = New York | publisher = Oxford University Press | page = [https://archive.org/details/garnersmodername00garn/page/654 654] | isbn = 0-19-516191-2 | url = https://archive.org/details/garnersmodername00garn/page/654 }}</ref> In Australia and Canada, the comma is typically avoided in non-academic publications unless its absence produces ambiguity.

It is important that the serial comma's usage within a document be consistent;<ref name=Fowlers2015/> inconsistent usage can seem unprofessional.<ref name=BusInsider/>

===Mainly American style guides supporting mandatory or typical use===
;The [[United States Government Printing Office]]'s ''Style Manual''
:"After each member within a series of three or more words, phrases, letters, or figures used with ''and'', ''or'', or ''nor''." It notes that an age ("70 years 11 months 6 days") is not a series and should not take commas.<ref name="usgo">{{cite book |chapter=8. Punctuation |year=2008 |title=GPO Style Manual |edition=30th |publisher=U.S. Government Printing Office |location=Washington, DC |isbn=978-0-16-081813-4 |page=201 |chapter-url=http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=2008_style_manual&docid=f:chapter8.pdf#page=9 |url=https://www.gpo.gov/fdsys/pkg/GPO-STYLEMANUAL-2008/html/GPO-STYLEMANUAL-2008-1.htm |access-date=June 9, 2010 |archive-date=August 31, 2024 |archive-url=https://web.archive.org/web/20240831005909/https://www.govinfo.gov/content/pkg/GPO-STYLEMANUAL-2008/html/GPO-STYLEMANUAL-2008-1.htm |url-status=live }}</ref>
;Wilson Follett's ''Modern American Usage: A Guide'' ([[Random House]], 1981), pp.&nbsp;397–401:
:"What, then, are the arguments for omitting the last comma? Only one is cogent – the saving of space. In the narrow width of a newspaper column this saving counts for more than elsewhere, which is why the omission is so nearly universal in journalism. But here or anywhere one must question whether the advantage outweighs the confusion caused by the omission. … The recommendation here is that [writers] use the comma between all members of a series, including the last two, on the common-sense ground that to do so will preclude ambiguities and annoyances at a negligible cost."<ref>{{cite web |title=The Case of the Serial Comma-Solved! |publisher=Swcp.com |url=http://www.swcp.com/info/essays/serial-comma.htm |access-date=February 10, 2013 |archive-date=December 5, 2008 |archive-url=https://web.archive.org/web/20081205035832/http://www.swcp.com/info/essays/serial-comma.htm |url-status=live }}</ref>
;''[[The Chicago Manual of Style]]'', 16th edition (University of Chicago Press, 2010), paragraph 6.18
:"When a conjunction joins the last two elements in a series of three or more, a comma … should appear before the conjunction. Chicago strongly recommends this widely practiced usage." In answer to a reader's query, ''The Chicago Manual of Style Online'' notes that their style guide has been recommending use of the serial comma ever since the first edition in 1906, but also qualifies this, saying "the serial comma is optional; some mainstream style guides (such as the [[Associated Press]]) don't use it. … there are times when using the comma (or omitting it) results in ambiguity, which is why it's best to stay flexible."<ref name="CMOS Online">{{cite web |date=January 6, 2016 |title=Browse Q & A: Commas |website=The Chicago Manual of Style Online |publisher=[[University of Chicago Press]] |url=http://www.chicagomanualofstyle.org/qanda/data/faq/topics/Commas/faq0066.html |access-date=March 3, 2018 |archive-date=March 3, 2018 |archive-url=https://web.archive.org/web/20180303165547/http://www.chicagomanualofstyle.org/qanda/data/faq/topics/Commas/faq0066.html |url-status=live }}</ref>
;''[[The Elements of Style]]'' (Strunk and White, 4th edition 1999), Rule 2<ref name="Strunk & White"/>
:"In a series of three or more terms with a single conjunction, use a comma after each term except the last." This has been recommended in ''The Elements of Style'' since the first edition by Strunk in 1918.<ref name="CMOS Online"/>
;The ''[[American Medical Association]] Manual of Style'', 9th edition (1998) Chapter 6.2.1
:"Use a comma before the conjunction that precedes the last term in a series."
;''[[APA style|The Publication Manual]] of the [[American Psychological Association]]'', 6th edition (2010) Chapter 4.03
:"Use a comma between elements (including before ''and'' and ''or'') in a series of three or more items."
;''The [[Council of Science Editors|CSE]] Manual for Authors, Editors, and Publishers'' (Council of Science Editors, 7th edition, 2006), Section 5.3.3.1
:"To separate the elements (words, phrases, clauses) of a simple series of more than 2 elements, including a comma before the closing 'and' or 'or' (the so-called serial comma). Routine use of the serial comma helps to prevent ambiguity."
;''[[Garner's Modern English Usage]]'', 4th edition (Oxford University Press, 2016), "Punctuation," § D, "Comma", p.&nbsp;748
:"Whether to include the serial comma has sparked many arguments. But it's easily answered in favor of inclusion because omitting the final comma may cause ambiguities, whereas including it never will{{snd}} e.g.: 'A and B, C and D, E and F[,] and G and H'."
;''MLA Style Manual and Guide to Scholarly Publishing'' ([[Modern Language Association]] 2008), paragraph 3.4.2.b
:"Use commas to separate words, phrases, and clauses in a series."
;''AAMT Book of Style for Medical Transcription''
:"Medical transcriptionists use the serial comma when two medications or diagnoses must be seen as separate; i.e., for 'The patient was on Aspirin, Coversyl, and Dilaudid', the comma is used before 'and' to avoid the reader erroneously thinking that Coversyl and Dilaudid must be taken together."<ref>The AAMT Book of Style for Medical Transcription, Claudia Tessier, {{ISBN|0-935229-22-1}}, Modesto, California, USA. Page 309.</ref>
;''AIP Style Manual'', American Institute of Physics, fourth edition, 1990
:"A comma goes before 'and' or 'or' in a series of three or more: Sn, K, Na, and Li lines are invisible."
;''Plain English Handbook'', Revised Edition (McCormick-Mathers Publishing Co., 1959), § 483, p.&nbsp;78
:"Use commas to separate the items in a series of words, phrases, or short clauses:
:The farmer sold corn, hay, oats, potatoes, and wheat."

===Mainly American style guides opposing typical use===
;''[[The New York Times]]'' stylebook<ref>{{cite news|title= Talk to the Newsroom: Director of Copy Desks Merrill Perlman|last= Perlman|first= Merrill|date= March 6, 2007|newspaper= The New York Times}}</ref>
:"In general, do not use a comma before ''and'' or ''or'' in a series."
;''The [[AP Stylebook]]''<ref>{{cite book| editor = Norman Goldstein| title = The Associated Press Stylebook and Briefing on Media Law| year = 2002| publisher = Perseus| location = Cambridge, Massachusetts| pages = [https://archive.org/details/associatedpress000gold/page/329 329–330]| isbn = 0-7382-0740-3| url = https://archive.org/details/associatedpress000gold/page/329}}</ref>
:"Use commas to separate elements in a series, but do not put a comma before the conjunction in a simple series. […] Put a comma before the concluding conjunction in a series, however, if an integral element of the series requires a conjunction: ''I had orange juice, toast, and ham and eggs for breakfast.'' Use a comma also before the concluding conjunction in a complex series of phrases: ''The main points to consider are whether the athletes are skillful enough to compete, whether they have the stamina to endure the training, and whether they have the proper mental attitude.'' In the United States, the choice is between journalistic style (no serial comma) and "literary" style (with serial comma); consistent use of the serial comma is usually recommended for college writing."<ref name=Gramlich>{{Cite journal|journal=Hohonu|year=2005|volume=3|issue=3|first=Andy|last=Gramlich|title=Commas: the biggest little quirks in the English language|page=71|url=https://hilo.hawaii.edu/campuscenter/hohonu/volumes/documents/Vol03x16Commas.pdf|access-date=December 17, 2013|quote=It's just a matter of STYLE, and in this case, newspaper or literary (book) style. . . . Choose one style or the other the authorities say, but be consistent. Most writers recommend the literary style in college writing to avoid possible confusion . . .|archive-date=August 7, 2020|archive-url=https://web.archive.org/web/20200807071316/https://hilo.hawaii.edu/campuscenter/hohonu/volumes/documents/Vol03x16Commas.pdf|url-status=live}}</ref>

===Mainly British style guides supporting mandatory or typical use===
;''[[MHRA Style Guide]]'' ([[Modern Humanities Research Association]]), 3rd edition (2013)<ref name=mhra>{{Cite book |title=MHRA Style Guide: a handbook for authors, editors, and writers of theses |edition=3rd |year=2013 |place=London |publisher=Modern Humanities Research Association |pages=33–4 |isbn=978-1-78188-009-8 |url=http://www.mhra.org.uk/Publications/Books/StyleGuide/index.html |access-date=April 19, 2013 |archive-date=November 5, 2018 |archive-url=https://web.archive.org/web/20181105003016/http://www.mhra.org.uk/Publications/Books/StyleGuide/index.html |url-status=dead }}</ref>
:"In an enumeration of three or more items, the practice in MHRA journals is to insert commas after all but the last item, to give equal weight to each enumerated element. … The conjunctions ''and'' and ''or'' without a preceding comma are understood as linking the parts of a single enumerated element"
:But paragraph 5.1<ref name=mhra/> says "The comma after the penultimate item may be omitted in books published by the MHRA, as long as the sense is clear."

===Mainly British style guides opposing typical use===
;''[[The Times]]'' style manual<ref>{{cite news|url= http://www.timesonline.co.uk/tol/tools_and_services/specials/style_guide/article986734.ece|title= Online Style Guide&nbsp;– P|access-date= March 22, 2008|date= December 16, 2005|newspaper= [[The Times]]|pages= (see ''punctuation/commas'')|location= London|first= Jeremy|last= Kelly|archive-date= September 24, 2011|archive-url= https://web.archive.org/web/20110924201316/http://www.timesonline.co.uk/tol/tools_and_services/specials/style_guide/article986734.ece|url-status= dead}}</ref>
:"Avoid the so-called ''Oxford comma''; say 'he ate bread, butter and jam' rather than 'he ate bread, butter, and jam'."
;''[[The Economist]]'' Style Guide<ref>{{cite news | url=http://www.economist.com/style-guide/commas | newspaper=The Economist | title=Style Guide | access-date=April 19, 2013 | date=October 18, 2011 | archive-date=September 23, 2017 | archive-url=https://web.archive.org/web/20170923130025/http://www.economist.com/style-guide/commas | url-status=live }}</ref>
:"Do not put a comma before ''and'' at the end of a sequence of items unless one of the items includes another ''and''. Thus 'The doctor suggested an aspirin, half a grapefruit and a cup of broth. But he ordered scrambled eggs, whisky and soda, and a selection from the trolley.{{'"}}
:"Sometimes it is essential: compare 'I dedicate this book to my parents, [[Martin Amis]], and [[JK Rowling]]' with 'I dedicate this book to my parents, Martin Amis and JK Rowling'."
;University of Oxford Public Affairs Directorate Writing and Style Guide (2016)<ref>{{cite web|url=http://www.ox.ac.uk/public_affairs/services_and_resources/style_guide/punctuation.html#acomma|title=Punctuation&nbsp;– University of Oxford|publisher=Public Affairs, University of Oxford|access-date=June 1, 2012|archive-date=March 30, 2014|archive-url=https://web.archive.org/web/20140330101320/http://www.ox.ac.uk/public_affairs/services_and_resources/style_guide/punctuation.html#acomma|url-status=dead}}</ref>
:"Note that there is generally no comma between the penultimate item and 'and'/'or' – this is sometimes referred to as the 'Oxford comma'. However, it is essential to use an Oxford comma if required to prevent ambiguity."

===Mainly British style guides that consider it generally unnecessary but discretionary===
;''[[The Guardian]] Style Guide''<ref>{{cite news |url=https://www.theguardian.com/styleguide/o |title=Guardian and Observer style guide: O |access-date=April 1, 2010 |work=The Guardian |location=London |date=December 19, 2008 |archive-date=November 9, 2013 |archive-url=https://web.archive.org/web/20131109084838/http://www.theguardian.com/styleguide/o |url-status=live }}</ref>
:"A comma before the final 'and' in lists: straightforward ones (he ate ham, eggs and chips) do not need one, but sometimes it can help the reader (he ate cereal, kippers, bacon, eggs, toast and marmalade, and tea)."
;''[[The Cambridge Guide to English Usage]]''<ref>{{cite book|last=Peters|first=Pam|author-link=Pam Peters|title=The Cambridge Guide to English Usage|year=2004|publisher=Cambridge University Press|location=Cambridge, England|isbn=0-521-62181-X|title-link=The Cambridge Guide to English Usage}}</ref>
:"In British practice there's an Oxford/Cambridge divide … In Canada and Australia the serial comma is recommended only to prevent ambiguity or misreading."
;''[[Fowler's Dictionary of Modern English Usage]]'', 4th edition, 2015<ref name="Fowlers2015">{{Cite book| last1=Fowler |first1=Henry Watson |editor1-last=Butterfield |editor1-first=Jeremy |title= Fowler's Dictionary of Modern English Usage |date=2015 |publisher=Oxford University Press |isbn=978-0-19-966135-0}}</ref>
:"The so-called 'Oxford comma' is an optional comma that follows the penultimate item in a list of three or more items and precedes the word 'and' … The general rule is that it should be used consistently or not at all … However, the Oxford comma can help to avoid ambiguity, ... and it is sometimes helpful to the reader to use an isolated serial comma for clarification, even when the convention has not been adopted in the rest of the text."
;''[[New Hart's Rules]]'', 2014<ref>{{cite book|title=New Hart's Rules: The Oxford Style Guide|date=2014|publisher=Oxford University Press|isbn=978-0-19-164914-1|url=https://books.google.com/books?id=l2pQBAAAQBAJ&pg=PT94}}</ref>
:"The general rule is that one style or the other should be used consistently. However, the last comma can serve to resolve ambiguity, particularly when any of the items are compound terms joined by a conjunction, and it is sometimes helpful to the reader to use an isolated serial comma for clarification even when the convention has not been adopted in the rest of the text."

===Australian style guides opposing typical use===
;The [[Australian Government Publishing Service]]'s ''Style Manual for Authors, Editors and Printers''<ref>{{cite web|url=http://www.australia.gov.au/about-government/publications/style-manual|title=Style manual - australia.gov.au|first=Digital Transformation|last=Agency|access-date=January 22, 2016|archive-date=March 12, 2016|archive-url=https://web.archive.org/web/20160312120942/http://www.australia.gov.au/about-government/publications/style-manual|url-status=live}}</ref>
:"A comma is used before ''and'', ''or'', or ''etc.'' in a list when its omission might either give rise to ambiguity or cause the last word or phrase to be construed with a preposition in the preceding phrase. … Generally, however, a comma is not used before ''and'', ''or'' or ''etc.'' in a list."

===Canadian style guides opposing typical use===
;Public Works and Government Services Canada Translation Bureau's ''The Canadian Style: A Guide to Writing and Editing''<ref>{{Cite book|url=https://archive.org/details/canadianstylegui0000unse|title=The Canadian style : a guide to writing and editing.|date=1997|publisher=Published by Dundurn Press in co-operation with Public Works and Government Services Canada, Translation Bureau, Canada. [[Translation Bureau]].|isbn=978-1-55002-276-6|edition=Rev and expanded|location=Toronto [Ont.]|oclc=244771093}}</ref>
:"Items in a series may be separated by commas:
:Complacency, urbanity, sentimentality, whimsicality
:They may also be linked by coordinating conjunctions such as ''and'' or ''or:''
:economists, sociologists or political scientists
:the good, the bad and the ugly
:Opinions differ on whether and when a comma should be inserted before the final ''and'' or ''or'' in a sequence. In keeping with the general trend toward less punctuation, the final comma is best omitted where clarity permits, unless there is a need to emphasize the last element in a series."

==Individual disputes==

===Maine labor dispute===
In the U.S. state of [[Maine]], the lack of a serial comma became the deciding factor in a $13 million lawsuit filed in 2014 that was eventually settled for $5 million in 2017. The U.S. appeals judge [[David J. Barron]] wrote, "For want of a comma, we have this case."<ref>{{cite news |url=https://www.washingtonpost.com/news/volokh-conspiracy/wp/2017/03/15/a-b-or-c-vs-a-b-or-c-the-serial-comma-and-the-law/ |first=Eugene |last=Volokh |title={{-'}}A, B or C' vs. 'A, B, or C' – the serial comma and the law |newspaper=[[The Washington Post]] |date=March 15, 2017 |access-date=March 19, 2017 |archive-date=March 16, 2017 |archive-url=https://web.archive.org/web/20170316044144/https://www.washingtonpost.com/news/volokh-conspiracy/wp/2017/03/15/a-b-or-c-vs-a-b-or-c-the-serial-comma-and-the-law/ |url-status=live }}</ref><ref>{{cite magazine |url=http://www.bostonmagazine.com/news/blog/2017/03/15/oxford-comma-maine-labor-dispute/ |first=Kyle Scott |last=Clauss |title=Oxford Comma Decides Court Case in Maine Labor Dispute |magazine=Boston Magazine |date=March 15, 2017 |access-date=March 15, 2017 |archive-date=March 15, 2017 |archive-url=https://web.archive.org/web/20170315183516/http://www.bostonmagazine.com/news/blog/2017/03/15/oxford-comma-maine-labor-dispute/ |url-status=live }}</ref><ref>{{cite news |first=Daniel |last=Victor |title=Lack of Oxford Comma Could Cost Maine Company Millions in Overtime Dispute |newspaper=[[The New York Times]] |date=March 16, 2017 |access-date=March 17, 2017 |url=https://www.nytimes.com/2017/03/16/us/oxford-comma-lawsuit.html?_r=2 |archive-date=August 10, 2017 |archive-url=https://web.archive.org/web/20170810092605/https://www.nytimes.com/2017/03/16/us/oxford-comma-lawsuit.html?_r=2 |url-status=live }}</ref>

In ''O'Connor v. Oakhurst Dairy'',<ref>{{Cite web |url=http://cases.justia.com/federal/appellate-courts/ca1/16-1901/16-1901-2017-03-13.pdf |title=''O'Connor v. Oakhurst Dairy'' |access-date=September 19, 2017 |archive-date=September 20, 2017 |archive-url=https://web.archive.org/web/20170920044120/http://cases.justia.com/federal/appellate-courts/ca1/16-1901/16-1901-2017-03-13.pdf |url-status=live }}</ref> a federal court of appeals was required to interpret a [[statute]] under which the "canning, processing, preserving, freezing, drying, marketing, storing, packing for shipment or distribution" of certain goods were activities exempted from the general requirement of overtime pay. The question was whether this list included the distribution of the goods, or only the packing of the goods ''for'' distribution. The lack of a comma suggested one meaning, while the omission of the conjunction ''or'' before "packing" and the fact that the ''Maine Legislative Drafting Manual'' advised against use of the serial comma suggested another. It said "Although authorities on punctuation may differ, when drafting Maine law or rules, don't use a comma between the penultimate and the last item of a series."<ref>{{cite web |title=Maine Legislative Drafting Manual 113 (Legislative Council, Maine State Legislature 2009) |url=http://maine.gov/legis/ros/manual/Draftman2009.pdf |access-date=March 4, 2018 |archive-date=November 19, 2017 |archive-url=https://web.archive.org/web/20171119111802/http://maine.gov/legis/ros/manual/Draftman2009.pdf |url-status=live }}</ref> In addition to the absence of a comma, the fact that the word chosen was "distribution" rather than "distributing" was also a consideration,<ref name=NewYorkerNorris>{{cite magazine |url=https://www.newyorker.com/culture/culture-desk/a-few-words-about-that-ten-million-dollar-serial-comma |title=A Few Words About That Ten-Million-Dollar Serial Comma |first=Mary |last=Norris |date=March 17, 2017 |access-date=March 3, 2018 |magazine=[[The New Yorker]] |archive-date=March 4, 2018 |archive-url=https://web.archive.org/web/20180304113154/https://www.newyorker.com/culture/culture-desk/a-few-words-about-that-ten-million-dollar-serial-comma |url-status=live }}</ref> as was the question of whether it would be reasonable to consider the list to be an [[Asyndeton|asyndetic]] list. Truck drivers demanded overtime pay; the defense conceded that the expression was ambiguous but said it should be interpreted as exempting distribution activity from overtime pay.<ref name=NewYorkerNorris/> The [[United States District Court for the District of Maine|district court]] agreed with the defense and held that "distribution" was an exempt activity. On appeal, however, the [[United States Court of Appeals for the First Circuit|First Circuit]] decided that the sentence was ambiguous and "because, under Maine law, ambiguities in the state's wage and hour laws must be construed liberally in order to accomplish their remedial purpose", adopted the drivers' narrower reading of the exemption and ruled that those who distributed the goods were entitled to overtime pay. Oakhurst Dairy settled the case by paying $5 million to the drivers,<ref>{{cite news|last1=Victor|first1=Daniel|title=Oxford Comma Dispute Is Settled as Maine Drivers Get $5 Million|url=https://www.nytimes.com/2018/02/09/us/oxford-comma-maine.html|access-date=February 9, 2018|work=The New York Times|date=February 9, 2018|archive-date=February 9, 2018|archive-url=https://web.archive.org/web/20180209210524/https://www.nytimes.com/2018/02/09/us/oxford-comma-maine.html|url-status=live}}</ref> and the phrase in the law in question was later changed to use serial semicolons and "distributing"{{snd}} resulting in "canning; processing; preserving; freezing; drying; marketing; storing; packing for shipment; or distributing".<ref>{{cite web |url=http://legislature.maine.gov/statutes/26/title26sec664.html |title=Title 26: Labor and Industry, Chapter 7: Employment Practices, Subchapter 3: Minimum wages, §664. Minimum wage; overtime rate |publisher=Maine Legislature official website |date=March 3, 2018 |access-date=March 3, 2018 |archive-date=March 15, 2018 |archive-url=https://web.archive.org/web/20180315001634/http://legislature.maine.gov/statutes/26/title26sec664.html |url-status=live }}</ref>

The opinion in the case said that 43 of the 50 U.S. states had mandated the use of a serial comma and that both chambers of the [[U.S. Congress|federal congress]] had warned against omitting it, in the words of the U.S. House Legislative Counsel's Manual on Drafting Style, "to prevent any misreading that the last item is part of the preceding one"; only seven states "either do not require or expressly prohibited the use of the serial comma".<ref name=Petelin>{{citation |url=http://www.abc.net.au/news/2017-03-21/the-case-of-the-$13-million-comma/8372956 |title=The case of the $13 million comma and why grammarians are rejoicing |first=Roslyn |last=Petelin |date=March 21, 2017 |access-date=March 3, 2018 |publisher=[[ABC News (Australia)|ABC News]] |location=Australia |archive-date=February 15, 2018 |archive-url=https://web.archive.org/web/20180215215854/http://www.abc.net.au/news/2017-03-21/the-case-of-the-$13-million-comma/8372956 |url-status=live }}</ref><ref name=USHouse/>

===British 50p Brexit coin===
In 2020, a [[Brexit 50p coin|commemorative 50p coin]] was brought into circulation in the United Kingdom to mark "[[Brexit]] day", January 31, 2020, minted with the phrase "Peace, prosperity and friendship with all nations". English novelist [[Philip Pullman]] and others criticized the omission of the serial comma, while others said it was an [[American English|Americanism]] and not required in this instance.<ref name="Brexit50p">{{cite news|last=Furness|first=Hannah|date=January 27, 2020|title=Author calls for Brexit coin 'boycott' over lack of Oxford comma|url=https://www.telegraph.co.uk/news/2020/01/27/author-calls-brexit-coin-boycott-lack-oxford-comma/|newspaper=[[The Daily Telegraph]]|location=London|url-status=live|archive-url=https://web.archive.org/web/20200127194852/https://www.telegraph.co.uk/news/2020/01/27/author-calls-brexit-coin-boycott-lack-oxford-comma/|archive-date=January 27, 2020}}</ref><ref>{{Cite web|url=http://www.theguardian.com/books/2020/jan/27/brexit-50p-coin-boycott-philip-pullman-oxford-comma|title=Philip Pullman calls for boycott of Brexit 50p coin over 'missing' Oxford comma|date=January 27, 2020|website=The Guardian|access-date=November 12, 2021|archive-date=August 31, 2024|archive-url=https://web.archive.org/web/20240831010250/https://www.theguardian.com/books/2020/jan/27/brexit-50p-coin-boycott-philip-pullman-oxford-comma|url-status=live}}</ref>

==See also==
* [[Roger Casement]], "hanged on a comma" due to contested non-punctuation in a law
* "[[Oxford Comma (song)|Oxford Comma]]", a 2008 song by [[Vampire Weekend]] which begins "Who gives a fuck about an Oxford comma?"
* [[Syndeton]], the conjunctive phrasing that may or may not contain a serial comma

==References==
{{reflist}}

{{DEFAULTSORT:Serial Comma}}
[[Category:American and British English differences]]
[[Category:Punctuation]]
[[Category:Punctuation of English]]
[[Category:English usage controversies]]