In writing authors' initials in research papers (either in the author by-line or the bibliography), should there be a space between intials?

  • R.P. Feynman
  • R. P. Feynman

What's the preferred way of writing it?

  • 10
    Whatever the journal you're trying to publish in wants. Feb 4, 2011 at 14:59
  • CMOS = complementary metal-oxide semiconductor? No, Chicago Manual of Style.
    – GEdgar
    Aug 25, 2021 at 15:25
  • lol, sorry. Figured that abbreviation was more common on this site. Editing... Aug 25, 2021 at 15:29
  • I've just checked the library catalogue for which I used to be responsible (it's some years since I retired!) and it has Rowling, J. K. with a space between the initials. Aug 25, 2021 at 15:32
  • 1
    I'm intrigued by the decision to merge, especially since (though I asked) Elem-Teach's question seemed to be focusing on the full-name-replacement usage and Kit's on the partial abbreviation. Aug 25, 2021 at 16:40

5 Answers 5


The periods in the initials stand for truncations, so you would put a space after each one. I don't think British English uses the initials, but I have seen various ways of doing it based on different style guides that govern different domains.

Check out the APA style guide, where they do use spaces:

Van Vugt, M., Hogan, R., & Kaiser, R. B. (2008). Leadership, followership, and evolution: Some lessons from the past. American Psychologist, 63(3), 182-196. doi:10.1037/0003-066X.63.3.182

The MLA style guide concurs:

Palmer, William J. Dickens and New Historicism. New York: St. Martin's, 1997. Print.

  • 1
    The MLA link says nothing about spacing, and with all due respect, the monospaced APA examples look nasty: monospace is for typewriters, not for typesetting. Moreover, Bringhurst disagrees; see my answer. Having a “space versus no-space” distinction probably only makes sense on a typewriter; with typesetting, other considerations apply.
    – tchrist
    Feb 27, 2013 at 21:02
  • Truncations did not require spaces back when acronyms where spelled with periods; the ones that still have them (Ph.D., e.g., i.e.) still don't require spaces.
    – Merk
    Oct 3, 2013 at 7:53
  • @tchrist: Your beef is with the MLA and APA style guides then. When I've submitted manuscripts in the past I was instructed to use Courier monospaced font because that's how editors prefer to see it. See this answer by JSBangs for further information.
    – Robusto
    Oct 8, 2013 at 0:50
  • 2
    There must be a typo in "I don't think British English uses the initials" it doesn't make sense otherwise (to me). Could you please clarify, maybe I'm misunderstanding something.
    – Mari-Lou A
    Sep 21, 2018 at 5:22

You certainly do not want to use full spaces within strings of initials. Indeed, you quite possibly do not want to use any spaces at all. It depends whether we are talking about text generated under the tyranny of the typewriter or text that is to be professionally typeset. With a typewriter, you should not use any spaces, but when typeset, smaller spaces are usually best.

One page 30 of version 3.2 of Robert Bringhurst’s Elements of Typographical Style, the de-facto “typesetter’s bible”, he writes:

2.1.5   Add little or no space within strings of initials.

Names such as W. B. Yeats and J. C. L. Prillwitz need hair spaces, thin spaces, or no spaces at all after the intermediary periods. A normal word space follows the last period in the string.

That was set with U+200A HAIR SPACE between each initial in the two strings of them. And I use “set” guardedly, considering that that was in HTML.

Even so, that probably looks terrible to you, but that is because web typography is almost always more primitive than even Gutenberg himself used. Notice for example that the placement of the dot in Georgia is distractingly far from its letter in the case of J and even worse for the W, and how it is so close to the L as to be nearly touching.

Properly set with correct kerning, that statement should read more like this:

image of correctly typeset

That’s basically what it looks like in the printed book, but I have greatly enlarged the font here to make it easier for you to see the differences.

As you see, the dots are now at a constant distance to the right of the letter immediately previous to them, and there are numerous other adjustments to make the text look less like a hastily typewritten ransom note and more like a printed book.

Those were set using U+200A HAIR SPACE just as in the HTML above it, but as you see, it looks infinitely better when properly typeset. That’s because it now has correct kerning and ligatures, and because the length of the line is now in balanced proportion to the x-height of the font — something that Stack Exchange has yet to get right.

  • 7
    I'd give this +2 if I could, because "less like a hastily typewritten ransom note and more like a printed book" thoroughly tickled me. Great answer. Oct 7, 2013 at 14:59
  • This would be of value for a publisher. It has little to do with the submission of manuscripts, especially for academic papers.
    – Robusto
    Oct 8, 2013 at 0:52
  • @tchrist I don’t think the problem of kerning is with Georgia, but with the working of the software. E.g. InDesign would kern properly if OPTICAL is used instead of METRICS (the default). With METRICS kerning used used, OP’s example of R.P. Feynman would look almost as bad in InDesign as in any other amateur application/website.
    – LWTBP
    May 21, 2015 at 6:12
  • 2
    @Robusto Please do not undervalue the importance of good typography in academic publishing of any kind. Yours, Copy Editor.
    – yo'
    Sep 1, 2015 at 10:53
  • 2
    @TheoYou It's because it is more comfortable to read lines of a certain length in running text. Bringhurst gives several different rules of thumb for sensible defaults, but all are shorter in ens than what Stack Overflow uses.
    – tchrist
    Feb 8, 2017 at 1:00

No spaces, no periods, as mentioned on the CMOS website:

Chicago style for initials that are used as a name is to take out the periods and close up the letters: BJ. Please see CMOS 8.4.

  • I actually saw that but wasn't sure how authoritative it was since it was just in the FAQs and "CMOS 8.4" which it references says nothing explicitly about the situation. Is the FAQ more trustworthy than I realized? Aug 25, 2021 at 16:07
  • 1
    Clarification: do we know whether this is only meant for usages in which the initialism is used as a name, i.e. replaces the full name in mode of address ("Hey, BJ!"), or also for partial abbreviation of a name. e.g. JK Rowling? Aug 25, 2021 at 16:07
  • 1
    This answers a question that was merged with this one, but not this question. Poor merge choice. Aug 25, 2021 at 20:54

Some journalism style guides recommend a space between the initials, and others recommend no space:


Peter Taylor's advice (above) is probably best: do whatever is customary in that journal.


Here's M-W's take in their Manual for Writers and Editors:

Personal Names
When initials are used with a surname, they are spaced and punctuated. Unspaced initials of a few famous person, which may or may not be punctuated, are sometimes used in place of their full names.

E. M. Forster
C. P. E. Bach
JFK or J.F.K.

When used as a first name, I see both in print:

“DJ said to let him know when you were up." ref.

As busy as I was, I took the time to stop and walk up to DJ and look him in the eye. ref

On our way home , Monique asked, "D.J., what do what do you think about me being queen of the ball?" ref.

His room was very messy, but D.J. loved his room. ref.

I think that authors can choose whichever they want. Perhaps we should respect a real person's own preference, e.g. Charlie or Charley for Charles, and D.J. or DJ, just as we do for pronunciation. I haven't come across a space between the initials when used as a first name.

  • This is similar to what CMOS has, but neither address the situation of "CJ", a non-famous person without surname. That's what my question is about. Aug 25, 2021 at 16:13
  • Examples added.
    – DjinTonic
    Aug 25, 2021 at 16:28

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