The Latin adverb sic ("thus", "just as"; in full: sic erat scriptum, "thus was it written")  inserted after a quoted word or passage indicates that the quoted matter has been transcribed or translated exactly as found in the source text, complete with any erroneous, archaic, or otherwise nonstandard spelling. It also applies to any surprising assertion, faulty reasoning, or other matter that might be likely interpreted as an error of transcription.
The usual usage is to inform the reader that any errors or apparent errors in quoted material do not arise from errors in the course of the transcription, but are intentionally reproduced, exactly as they appear in the source text. It is generally placed inside square brackets to indicate that it is not part of the quoted matter.
Sic may also be used derisively by the proofreader, to call attention to the original writer's spelling mistakes or erroneous logic, or to show general disapproval or dislike of the material. 
Though occasionally misidentified as an abbreviated word, sic is a Latin adverb used in English as an adverb, and, derivatively, as a noun and a verb. 
On occasion, sic has been misidentified as an acronym (and therefore sometimes misspelled with full stops/periods): "s.i.c." is said to stand for "spelled in context", "said in copy", "spelling is correct", "spelled incorrectly", and other such folk etymology phrases.  These are all incorrect and are simply backronyms from sic.
Use of sic greatly increased in the mid-twentieth century.  For example, in United States state-court opinions before 1944, sic appeared 1,239 times in the Westlaw database; in those from 1945 to 1990, it appeared 69,168 times.  The "benighted use" as a form of ridicule, deserved or otherwise, has been cited as a major factor in this increase. 
Sic, in its bracketed form, is most often inserted into quoted or reprinted material to indicate meticulous accuracy in reproducing the preceding text, despite appearances to the reader of an incorrect or unusual orthography ( spelling, punctuation, grammar, syntax, fact, logic, etc.).   Several usage guides recommend that a bracketed sic be used primarily as an aid to the reader, and not as an indicator of disagreement with the source.  
A sic may show that an uncommon or archaic expression is reported faithfully,  such as when quoting the U.S. Constitution: "The House of Representatives shall chuse [sic] their Speaker ..." Several writing guidebooks discourage its use with regard to dialect, such as in cases of American and British English spelling differences.    The appearance of a bracketed sic after the word analyse in a book review led Bryan A. Garner to comment, "... all the quoter (or overzealous editor) demonstrated was ignorance of British usage". 
Various wordplay employing the word sic is possible, arising either from its secondary meaning, " to attack", or from its homophone sick. For example, "Poor grammar makes me [sic]" has been featured on garments and postcards.  
In a different vein, a letter to the American Journal of Roentgenology suggested that the overuse of sic as a kind of linguistic discrimination against non-native writers of English "could lead readers to become 'sick of your sic'". 
The use of sic can be seen as an appeal to ridicule, whether intentional or not, because it highlights perceived irregularities. The application of sic with intent to disparage has been called the "benighted use" because it reflects a "false sense of superiority" in its users.  The following example from The Times of London demonstrates how the interpolation of sic can discredit a quoted statement.[ improper synthesis?]
Warehouse has been around for 30 years and has 263 stores, suggesting a large fan base. The chain sums up its appeal thus: "styley [sic], confident, sexy, glamorous, edgy, clean and individual, with it's [sic] finger on the fashion pulse." 
Occasionally a writer places [sic] after his own words, to indicate that the language has been chosen deliberately for special effect, especially where the writer's ironic meaning may otherwise be unclear.  Bryan A. Garner dubbed this use of sic "ironic", providing the following example from Fred Rodell's 1955 book Nine Men: 
[I]n 1951, it was the blessing bestowed on Judge Harold Medina's prosecution [sic] of the eleven so-called 'top native Communists,' which blessing meant giving the Smith Act the judicial nod of constitutionality.
Where sic follows the quotation, it takes brackets: [sic].  The word sic is usually treated as a loanword that does not require italics, and the style manuals of New Zealand, Australian and British media outlets generally do not require italicisation.  However, italicization is common in the United States, where authorities including APA Style insist upon it. 
Because sic is not an abbreviation, placing a full stop/period inside the brackets after the word sic is erroneous,   although at least one style guide suggests styling it as a parenthetical sentence only when used after a complete sentence, like so: (Sic).  It is occasionally followed by an exclamation mark, perhaps more indicative of derision.
Use of sic has been noted for its potential to bring about linguistic discrimination. A letter written to the American Journal of Roentgenology (AJR) has been cited in the journal's French counterpart, the Journal de Radiologie, highlighting how apparent prejudices among English-language journals may be causing a higher rejection rate of scholarly papers from francophone authors  – a concern because English is the lingua franca for medicine.  In the letter, the AJR was criticized for its frequent insertion of sic when publishing letters written by French and Japanese authors even though its correspondence acceptance policy reserved the right of copy-editing, which could therefore have been used beneficially to correct minor English language errors made by non English-speakers. In response, Lee F. Rogers, the Editor in Chief of AJR, apologized for the possible discriminatory interpretation and offered the following explanation for its decision to insert sic on multiple occasions rather than to copy-edit: 
It is true that our manuscript editors normally remedy errors in the use of the English language to ensure reader understanding and to avoid embarrassing our non–English-speaking authors. However, because of the seriousness of the allegations addressed, we believed that verbatim quotes were necessary. Under such circumstances, we did not think it correct for us to assume the meaning of misspelled words or the intent of the author of the letter in question.
Some guides, including The Chicago Manual of Style, recommend "quiet copy-editing" (unless where inappropriate or uncertain) instead of inserting a bracketed sic, such as by substituting in brackets the correct word in place of the incorrect word or by simply replacing an incorrect spelling with the correct one.  
|Look up recte in Wiktionary, the free dictionary.|
Alternatively, to show both the original and the suggested correction (as they often are in palaeography), one may give the actual form, followed by recte, then the corrected form, in brackets. The Latin adverb recte means rightly. 
An Iraqi battalion has consumed [recte assumed] control of the former American military base, and our forces are now about 40 minutes outside the city.
According to the Journal of Seventeenth-Century Music Style Sheet, there should be no punctuation, for example no colon, before the corrected word when using recte. 
A third alternative is to follow an error with sic, a comma or colon, "read", and the correct reading, all within square brackets, as in the following example:
'Plan of space alongside Evinghews [sic: read Evening News] Printing Works and overlooked by St. Giles House University Hall' 
|Look up sic in Wiktionary, the free dictionary.|
- List of Latin phrases
- Sic et Non
- Sic semper tyrannis
- Sic transit gloria mundi
- Dictated but not read
- Footnotes, 1, in opinion of November 15, 2012 in U.S. v. Bryant, Case No. 11-CR-20034. (Federal judge noted using variant spelling of Bryant's given name, "'sic erat scriptum'" in court document.)
- Garner, Bryan A. (2001). "sic". A dictionary of modern legal usage (2nd ed.). USA: Oxford University Press. pp. 806–807. ISBN 978-0-19-514236-5.
- "sic, adv. (and n.)" Oxford English Dictionary, Second Edition 1989. Oxford University Press
- 3sic. Merriam-Webster's collegiate dictionary. Merriam-Webster, 2003. ISBN 0-87779-809-5, ISBN 978-0-87779-809-5. (p.1156)
- Cassell's Latin Dictionary
- "sic, adv. (and n.)" Oxford English Dictionary, Second Edition 1989. Oxford University Press; see also E. Belfort Bax. "On Some Forms of Modern Cant". Commonweal: 7 May 1887. Marxists' Internet Archive: 14 Jan. 2006
- e.g. "Thefreedictionary.com". Retrieved 2014-04-10.
- Bryan A. Garner. The Oxford dictionary of American usage and style. Oxford University Press US, 2000. ISBN 0-19-513508-3, ISBN 978-0-19-513508-4
- Leon Edel's "Introduction" to Henry James Letters (Volume 1, 1843 – 1875). Harvard University Press, 1974. ISBN 0-674-38780-5, ISBN 978-0-674-38780-5
- " Grammar and Style." USD History Guide for Writing Research Papers. Department of History, University of South Dakota. 6/12/2009
- William Coyle and Joe Law (2009). Research Papers. Cengage Learning. p. 72. ISBN 0-547-19081-6.
- Carillo, Jose A. (March 6, 2010). "The role of the bracketed 'sic' in English prose". The Manila Times. Archived from the original on May 27, 2012.
- Remero, Donald (May 9, 2010). "Quoting British / American English". ieosetta.com. Archived from the original on October 13, 2010.
- "Poor Grammar Makes Me Sic Sweatshirts & Hoodies". CafePress. Accessed: October 1, 2010.
- "Somewhat Topical Ecards". someecards.com. Retrieved October 1, 2010.
- Arrivé, Lionel (2001). "Try Writing It in French or in Japanese". American Journal of Roentgenology. 176 (2): 548. doi: 10.2214/ajr.176.2.1760548. PMID 11159116.
- Ashworth, Anne (2006-06-21). "Chain reaction: Warehouse". The Times. Archived from the original on September 29, 2006. Retrieved 2016-05-20.
- H. W. Fowler (2001) A Dictionary of Modern English Usage. Oxford : Oxford University Press, p. 807. ISBN 978-0-19-953534-7
- Jessen, Edward W. (2000). California Manual of Style: A Handbook of Legal Style for California Courts and Lawyers (4th edition) (PDF). pp. 132–133. Retrieved 2015-08-10.
- "Parentheses, Ellipses, and Brackets" (PDF). Writing Center. Johnson County Community College. Archived from the original (PDF) on 2012-08-31. Retrieved 19 November 2014.
- Quotations. The Writing Center, University of North Carolina at Chapel Hill. Accessed: October 2, 2010
- Wilson, Kenneth G. (1993). "sic (adv.)". The Columbia Guide to Standard American English. Columbia University Press. Retrieved 2009-11-03.
- Arrivé, L; Dono, P; Lewin, M; Dahan, H; Monnier-Cholley, L; Tubiana, JM (December 2001). "Taux de publication des travaux originaux présentés oralement lors des journées françaises de radiologie 1996" [Publication rate of papers originally presented at the national french congress of radiology in 1996]. Journal de Radiologie (in French). 82 (12): 1719–22. PMID 11917637. Archived from the original on 2011-10-04.
"Style Q&A: Quotations and Dialogue". The Chicago Manual of Style Online. Retrieved 28 September 2018.
In paragraph 13.7, in the section on permissible changes to quotations, CMOS says, ‘Obvious typographic errors may be corrected silently (without comment or sic) unless the passage quoted is from an older work or a manuscript source where idiosyncrasies of spelling are generally preserved.’
- Janet Fairweather. Liber Eliensis. Boydell Press, 2005. ISBN 1-84383-015-9, ISBN 978-1-84383-015-3. (p. xxix)
- Bruce Gustafson. JSCM Style Sheet. Journal of Seventeenth-Century Music, 2 January 2010.
- "Item 26 - 'Plan of space alongside Evinghews [sic: read Evening News] Printing Works and overlooked by St. Giles House University Hall', [Edinburgh]". University of Strathclyde Archives. Retrieved 19 November 2014.