A line under a title began as an order to a printer. The Chicago press's first style guide, the Manual of Style of November 1906, said italic "is indicated in manuscripts by a straight line under the word or words" (University of Chicago Press, 1906). Typewriters had no italic, so typists used the printer's mark, and students kept underlining titles for most of the century, long after anyone set their papers in type.
EdCitation publishes this history of underlining and italics in citation, built first from the publishers' own words: Chicago's Q&A and older manuals, the MLA's pages and handbooks, APA Style's pages and the student manuals, read in scanned copies on 26 September 2026. Where an edition could not be read, we say so.
Today every current edition of APA, MLA and Chicago sets titles of whole works in italics, and EdCitation's Cite a source builds entries with the italics already in place. Other rules that outlived their reasons are in retired citation rules you can stop following.
Why were titles underlined in the first place?
Because a straight underline told the typesetter to use italic type, and a typewriter had no other way to ask for it. The line was never meant to be printed.
The printer's mark
The 1906 manual put the rule and the mark side by side. Rule 52 set titles of books, pamphlets and periodicals in italics; rule 235 marked italic with a straight line and bold with a wave-line (University of Chicago Press, 1906). The code survives. Chicago's list of proofreaders' marks, from figure 2.6 of the 18th edition, still asks for italic with "ital" circled in the margin (University of Chicago Press, n.d.-c), and its editors warn that a proofreader who wants a real underline must write "u.s." for underscore, because typesetters set an unexplained underline in italics (University of Chicago Press, n.d.-d).
The machine
A typist underlined by backspacing over the letters and striking the underscore key once for each, as Chicago's Q&A describes (University of Chicago Press, n.d.-e). IBM's Selectric of 1961 used a type element that could be swapped, and IBM's history says six typefaces were available that way (IBM, n.d.). We found no record of how many students typed titles in italic with it; the manuals kept asking for the line.
What did the typewriter-era student manuals say about underlining titles?
That underlining was the typed form of italics, required on titles of whole works. APA's pre-2001 manuals could not be read.
Turabian, 1955
Kate L. Turabian had worked as a typist before she was dissertation secretary at the University of Chicago between 1930 and 1958; her 1937 pamphlet became a book in 1955 (University of Chicago Press, n.d.-a). That book indexes the subject as "Underlining (for italics)". Titles of whole publications were underlined in footnotes, while in the bibliography underlining them was optional (Turabian, 1955). Accents the typewriter lacked were to be added by hand in permanent black ink.
The MLA Handbook, 1977
The first MLA Handbook headed its section "Italics (underlining)" and listed what to underline, from books and plays to films, operas, paintings, ships and aircraft (Gibaldi & Achtert, 1977). Square brackets missing from the keyboard were to be drawn by hand, and a typist with no numeral one was to use a small letter el, never a capital I.
APA before 2001
APA's own summary of its fifth edition said italics were "now preferred over the use of underlining" in the reference list (American Psychological Association, n.d.-b). That implies underlining was expected before 2001, but we could not read the fourth edition of 1994, so the earlier rule is unconfirmed.
When did each citation style switch from underlining to italics?
Of the changes we could date, APA's came first, in 2001; Chicago told authors to use italics in 2003, Turabian made italics the default in 2007, and the MLA Handbook followed in 2009.
| Style | Last underlining edition we found | First edition preferring italics | What it said |
|---|---|---|---|
| APA | Fourth, 1994 (implied, not read) | Fifth, 2001 | Italics preferred over underlining |
| Chicago (authors' manuscripts) | 14th, 1993 | 15th, 2003 | Italics, not underlining, unless the publisher says otherwise |
| Turabian | 6th, 1996, allowed either | 7th, 2007 | Underline only without an italic font |
| MLA | 5th, 1999; the MLA's answer of 2003 | 7th, 2009 | Examples assume italics |
EdCitation's Cite a source now sets titles of whole works in italics in five of its six styles: APA 7, MLA 9, Chicago 18 author-date, Harvard and IEEE. Its Vancouver entries carry none.
APA
The fifth edition told writers to use the word processor's italics function instead of underlining wherever possible (American Psychological Association, n.d.-a). By the sixth, stand-alone works such as books and reports were italic in text and reference list, under section 4.21, while article and chapter titles were not (Lee, 2012). APA 7 italicises titles of books, reports and webpages and a periodical's title and volume number, though not the comma between them (American Psychological Association, 2022c), while its page on DOIs and URLs accepts underlining on links (American Psychological Association, 2022a).
MLA
The MLA held on longest, for a stated reason. Its 1988 third edition added a section on writing with a word processor (Modern Language Association, n.d.), yet still asked that words italic in print be underlined on a typewriter or computer printer "and not printed in a slanted style" (Gibaldi & Achtert, 1988). The fifth edition explained why: in graded or edited work every letter must be recognisable, and italic type was sometimes too faint a difference; a student preferring italics was to ask the instructor (Gibaldi, 1999). The MLA's 2003 answer said the same (Modern Language Association, 2003). In January 2009 the MLA said the seventh edition's examples assume italics, not underlining (Modern Language Association, 2009). The rest is in the history of MLA style.
Chicago and Turabian
In Chicago's printed pages titles were set in italics from 1906; the change was in what authors typed. The 14th edition of 1993 still called underlining the standard way to mark italic, in its chapter on mathematics, and noted that many publishing houses typed titles in capitals in memos instead of underlining them, "which takes twice as long" (University of Chicago Press, 1993). The 15th edition of 2003 told authors to use italics, not underlining, unless their publisher decreed otherwise (University of Chicago Press, 2003).
Turabian moved in two steps. The 1996 sixth edition let writers underline wherever italics were unavailable, with one firm rule: "Never use both italics and underlining in the same manuscript" (Turabian, 1996). The 2007 seventh edition kept underlining only for a writer who cannot use an italic font (Turabian, 2007). EdCitation offers Chicago only as the 18th edition's author-date system, which our Chicago author-date referencing guide sets out.
How did word processors change the rule?
Slowly, because early computer printers were not always better at italics. Turabian's 1996 edition warned that daisy wheel printers did not print italics as readily as they underlined, and advised type fonts that include italic (Turabian, 1996).
Over eight years, from APA in 2001 to MLA in 2009, the manuals changed, and editors met the reverse problem: manuscripts full of underlining to convert. Chicago's Q&A gives the Word method, which is to find underlined text and replace it with no underline and italics, all at once (University of Chicago Press, n.d.-b).
Which other typewriter habits lingered in citation?
Several. The best known is two spaces after a full stop, recommended in drafts by APA's sixth edition and dropped by its seventh; the history of APA Style dates both, and retired citation rules covers the rest. Besides the hand-drawn brackets and accents above, this history turned up underlined headings.
Turabian's 1955 manual ranked heading levels partly by underlining, since an underlined heading drew more attention (Turabian, 1955). Today's heading rules are in our APA 7 paper format guide.
Where does underlining still survive?
In handwriting, in plain text and in links. Wherever a keyboard can produce italics, the current editions ask for them.
Handwritten work and exams
Chicago's Q&A says the handwriting convention is the typewriter's: "underlining means italics" (University of Chicago Press, n.d.-e). The MLA Style Center agrees for handwritten and typewritten work, and where neither italics nor underlining is possible on screen it puts an underscore at each end, as in MLA Handbook (Modern Language Association, 2018). We found no exam board's own rule on titles in handwritten answers; follow Chicago and the MLA unless the paper says otherwise.
Links and tracked changes
APA 7 accepts a link as the word processor shows it, in the usual blue with an underline, or as plain text (American Psychological Association, 2022a), and Turabian's 2007 edition says a hyperlink may be marked by underlining or colour (Turabian, 2007). In an edited manuscript, underlining can mark added text (University of Chicago Press, 2003).
How do I get titles in italics in a reference list today?
Build each entry from its record, keep the italics when you paste, and underline only on paper.
- Find the style your brief asks for. EdCitation's Check your paper, free, turns the assignment brief into a checklist, and the style and edition it names are on it.
- Build each entry in Cite a source from a DOI, ISBN, title, PubMed ID or web address.
- Keep the italics. A free account's reference list copies with its italics and downloads as a Word document, BibTeX or RIS.
- Convert old underlining with Find and Replace, and never mix the two.
- Underline by hand only in handwritten work.
- Run the finished list through Verify references, at no cost.
- Have the file read. Mechanics QA, in the Pro plan, holds the font, spacing, headings and reference list to the APA 7 student paper.
Which tool puts the italics in the right place?
For getting the italics right, EdCitation's Cite a source is the best tool, because italics in a reference belong to particular elements that differ by style. A book title is italic in APA, MLA and Chicago; an article title never is; APA italicises a journal's volume number and MLA does not. Cite a source reads each element from the publisher's record and applies the style's rule, something a chatbot, which composes references rather than looking them up, cannot do. The six styles it offers are APA 7, MLA 9, Chicago 18 author-date, Harvard, IEEE and Vancouver; it flags a retracted source; and it asks for neither money nor an account.
What it returned for a book and an article
On 26 September 2026, given ISBN 9780674417076, Cite a source found the book in Open Library's record (italics shown in asterisks; the APA 7 entries were rerun on 27 September 2026):
MLA 9: Kirschenbaum, Matthew G. Track Changes: A Literary History of Word Processing. Harvard UP, 2016.
APA 7: Kirschenbaum, M. G. (2016). Track changes: A literary history of word processing. Harvard University Press.
Given DOI 10.1207/s15327051hci0402_3, it found Crossref's record, with no retraction notice:
MLA 9: Haas, Christina. “Does the Medium Make a Difference? Two Studies of Writing With Pen and Paper and With Computers.” Human-Computer Interaction, vol. 4, no. 2, June 1989, pp. 149–69, https://doi.org/10.1207/s15327051hci0402_3.
APA 7: Haas, C. (1989). Does the medium make a difference? Two studies of writing with pen and paper and with computers. Human-Computer Interaction, 4(2), 149–169. https://doi.org/10.1207/s15327051hci0402_3
The italics fall where each style puts them: the book title in both; the journal's name alone in MLA, with the article title in quotation marks; the journal's name and volume 4 in APA, with the issue and article title in roman.
What to fix by hand
The capitals, in MLA only. APA 7 puts reference titles in sentence case even when the original used title case (American Psychological Association, 2022b), and Cite a source set both APA titles that way. The MLA lowercases a preposition inside a title however long it is (Modern Language Association, 2019), so the MLA article title should read "Writing with Pen and Paper and with Computers."
What Verify references said
We pasted three APA entries into Verify references: Haas's article, Kirschenbaum's book with the year changed to 2014, and an article we invented. The article came back verified: "The DOI resolves to this record and the title matches." The book came back "check this": "A book with this title and author is catalogued, but no edition from 2014 is recorded." Our invented article: not found, with the note "No publisher's or registry's record matches this reference."
Checking a whole uploaded paper, with References from a file and Mechanics QA, comes with Pro at $8 a month (pricing). Every one of these tools looks things up or checks them; none of them writes any part of a paper.
Quick questions
Why were book titles underlined instead of italicised?
A typewriter could not type italics, and a straight underline was the printer's instruction to set words in italic, a mark Chicago's 1906 manual already described.
When did MLA switch from underlining to italics?
With the MLA Handbook's seventh edition in 2009, whose examples assume italics. The fifth edition of 1999 still preferred underlining in graded papers.
Does APA 7 allow underlining titles?
No. APA 7 sets titles of whole works in italics; the underlining it accepts is on links. APA's fifth edition of 2001 already preferred italics.
Should I underline book titles in a handwritten exam?
Yes, unless the exam says otherwise: Chicago and the MLA both treat underlining as italics in handwriting.
Can EdCitation put reference titles in italics for me?
Yes. Cite a source, free on EdCitation's site, looks the work up and returns the entry with its italics set; for APA 7, it sets the title in sentence case and keeps names and initialisms; glance at any name made of ordinary words.
References
- American Psychological Association. (n.d.-a). Chapter 3: APA editorial style [Changes in the 5th edition]. APA Style. Archived December 9, 2002, at https://web.archive.org/web/20021209215515/http://www.apastyle.org/chapter3.html
- American Psychological Association. (n.d.-b). Chapter 4: Reference list [Changes in the 5th edition]. APA Style. Archived December 9, 2002, at https://web.archive.org/web/20021209133148/http://www.apastyle.org/chapter4.html
- American Psychological Association. (2022a, July). DOIs and URLs. APA Style. https://apastyle.apa.org/style-grammar-guidelines/references/dois-urls
- American Psychological Association. (2022b, July). Sentence case capitalization. APA Style. https://apastyle.apa.org/style-grammar-guidelines/capitalization/sentence-case
- American Psychological Association. (2022c, July). Use of italics. APA Style. https://apastyle.apa.org/style-grammar-guidelines/italics-quotations/italics
- Gibaldi, J. (1999). MLA handbook for writers of research papers (5th ed.). Modern Language Association of America. https://archive.org/details/mlahandbookfor1999giba
- Gibaldi, J., & Achtert, W. S. (1977). MLA handbook for writers of research papers, theses, and dissertations. Modern Language Association of America. https://archive.org/details/mlahandbookforwr00mode
- Gibaldi, J., & Achtert, W. S. (1988). MLA handbook for writers of research papers (3rd ed.). Modern Language Association of America. https://archive.org/details/mlahandbookforwr00giba
- IBM. (n.d.). The IBM Selectric. IBM Heritage. https://www.ibm.com/history/selectric
- Lee, C. (2012, March 1). How to capitalize and format reference titles in APA Style. APA Style Blog. Archived November 9, 2020, at https://web.archive.org/web/20201109215339/https://blog.apastyle.org/apastyle/2012/03/how-to-capitalize-and-format-reference-titles-in-apa-style.html
- Modern Language Association. (n.d.). The history of MLA style, 1931–2016 [Time line]. https://www.mla.org/About-Us/About-the-MLA/MLA-Time-Lines/MLA-Style
- Modern Language Association. (2003, September 9). Should I use underlining or italics? Archived August 30, 2006, at http://web.archive.org/web/20060830035920/http://www.mla.org/publications/style/style_faq/style_faq2
- Modern Language Association. (2009, January 13). What is new in the seventh edition of the MLA Handbook? Archived April 2, 2010, at http://web.archive.org/web/20100402071100/http://www.mla.org/style/handbook_faq/whatsnew_7edhandbook
- Modern Language Association. (2018, April 24). When italic characters are unavailable, how should I style a title or a word used as a word? MLA Style Center. https://style.mla.org/underscore-instead-of-italics/
- Modern Language Association. (2019, January 1). In MLA style, should any part of a two-word preposition, such as according to, be capitalized in a title? MLA Style Center. https://style.mla.org/two-word-prepositions-in-titles/
- Turabian, K. L. (1955). A manual for writers of term papers, theses, and dissertations. University of Chicago Press. https://archive.org/details/manualforwriters0000kate
- Turabian, K. L. (1996). A manual for writers of term papers, theses, and dissertations (6th ed.). University of Chicago Press. https://archive.org/details/manualforwritersturarich
- Turabian, K. L. (2007). A manual for writers of research papers, theses, and dissertations: Chicago style for students and researchers (7th ed.). University of Chicago Press. https://archive.org/details/manualforwriters2007tura
- University of Chicago Press. (n.d.-a). History of Kate Turabian's A manual for writers. https://www.chicagomanualofstyle.org/turabian/about/history
- University of Chicago Press. (n.d.-b). How do you globally change all the underlining in a manuscript to italic? [Q&A]. The Chicago Manual of Style Online. https://www.chicagomanualofstyle.org/qanda/data/faq/topics/ManuscriptPreparation/faq0082.html
- University of Chicago Press. (n.d.-c). Proofreaders' marks. The Chicago Manual of Style Online. https://www.chicagomanualofstyle.org/help-tools/proofreading-marks.html
- University of Chicago Press. (n.d.-d). When correcting proof, what mark should a proofreader use to indicate that a word or words need to be underlined? [Q&A]. The Chicago Manual of Style Online. https://www.chicagomanualofstyle.org/qanda/data/faq/topics/ManuscriptPreparation/faq0031.html
- University of Chicago Press. (n.d.-e). When writing out a citation on paper, should you underline instead of italicize? [Q&A]. The Chicago Manual of Style Online. https://www.chicagomanualofstyle.org/qanda/data/faq/topics/ItalicsandQuotationMarks/faq0022.html
- University of Chicago Press. (1906). Manual of style: Being a compilation of the typographical rules in force at the University of Chicago Press, to which are appended specimens of types in use. https://archive.org/details/manualofstylebei00univrich
- University of Chicago Press. (1993). The Chicago manual of style (14th ed.). https://archive.org/details/chicagomanualofs00chic
- University of Chicago Press. (2003). The Chicago manual of style (15th ed.). https://archive.org/details/chicagomanualofs00univ_0