Editing Serial comma (section)

===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."