March 27, 2008

Weekly Language Usage Tips (March 27, 2008) periods in abbreviations, underlining and spacing

Posted in abbreviations, periods in abbreviations, underlining and spacing at 7:07 pm by dlseltzer

Tip 1: Using periods in abbreviations

The use of periods in abbreviations is largely a matter of convention and, over time, the convention has increasingly moved to less use of periods in abbreviations. To make sure that I wasn’t misleading you on this issue, I consulted my style books, and the only book that did not concur was my US Government Printing Office Style Manual from 1973. I view the GPO Style Manual these days as a source of amusement and nostalgia but at one time, it was useful and it was a present for my college graduation (I don’t know which is sadder–that the book and I have gotten so old or that the book was someone’s idea of a good graduation present). Here are a few rules for using periods in abbreviations:

If the abbreviation is all lower case, use periods (e.g., i.e., a.m., etc., p.m., assn., pp. ). There are many exceptions to this (e.g., mph, cd, ft, yr, rom), but as a general rule, this works pretty well.

Do not use periods in degrees (e.g., MD, PhD, MBA, MSc, MPH, MPP, BS).

Do not use periods in acronyms or initialisms, that is, first-letter abbreviations (e.g., NATO, CRHC, GSPH, CHERP, UNICEF).

NOTE: While some people (including me) consider all of the examples, here, to be acronyms, others only consider those that can be pronounced as words to be acronyms (e.g., UCSUR, WPIC [when pronounced “wipick”], QALY, AHRQ [when pronounced “ark”]) and all others to be initialisms, that is, abbreviations where each letter is pronounced as a letter (e.g., BMI, CEA, CPA, IRS, DoD, NIH). Whatever terminology you use, they are all treated the same way with respect to periods–there are none.

Do not use periods in abbreviated names of countries (e.g., US, UK, NZ, AUS) or states if you are using the two digit post office designation (e.g., PA but Penn.)

If the abbreviation ends in a lower case letter, use periods (e.g., Dr., Mr., Mrs., Co., Ltd.). Again there are exceptions (e.g., Pitt, UConn, Cmd, Opt).

There are lots of other conventions. Let me know if there are any we should discuss here.

Tip 2: Relics: Underlining and spacing


Some of you have heard this from me before and can probably quote me on it but it still needs to be said: Underlining is a relic of the typewriter and should NEVER be used. In the old days of typewriters, there was no way to show emphasis other than through underlining. There were no “bold” and “italic” features. Underlining text was a way of indicating that the typesetter should italicize that text during the typesetting process. Now, we use word processors and can Bold and italicize words ourselves, and there is no need to underline anymore. Why not underline? It’s ugly. It doesn’t enhance the reading experience, in fact, it detracts. Instead of reading one character at a time, you are forced to read two: the letter and the line. Finally, there is no elegance to the underline. Since there are other, more elegant ways to impart emphasis, there is no need to use underlining. Pick up a few books at random, and look through them. You will rarely see an underline, and I would bet that books that do contain underlining are not put out by an established publishing house. Don’t underline and I can’t emphasize that enough.


Another relic of using typewriters is putting two spaces at the end of a sentence. This was done because the typeface used by the typewriter was Courier and Courier is a non-proportional typeface. In proportional type, the width of each font varies according to the letter it reflects, that is, an “i” or an “l” would be thinner than a “w” or an “m.” In Courier, the type is non-proportional, and all characters, whether an “i” or a “w,” are the same width. Courier: “i” and “w.” Your computers still have Courier on them for writing source code so you can try it for yourself. But, we are getting off the point. Because all characters were the same width, it was difficult to find the end of a sentence. The two spaces signaled the end of a sentence. Now, proportional typefaces are used virtually all of the time and they are easier to read, so it is no longer necessary to use two spaces at the end of a sentence. And for grant proposal writers, changing two spaces to one will save you a few lines, and we need every line we can get in a proposal.

An aside: There is a difference between typefaces and fonts although the difference is quickly eroding. But for those who are interested: A typeface is the design of the lettering. A font represents the specific attributes of a member of that typeface. While Times New Roman is a typeface, Times New Roman bold, italic 12 pt is a font.



  1. dlseltzer said,

    From a reader:

    THANK YOU THANK YOU THANK YOU. Using two spaces at the end of a sentence has always been a major pet peeve of mine! I always corrected people’s manuscripts to a single space, and, unfortunately, they often always changed them back to two spaces!
    Thanks for setting the record straight.

  2. dlseltzer said,

    From a reader:

    Thank you very much for clarifying this issue. I have never used periods after my degrees, but it amazes me how often this occurs.

    Joe Pompous, B.S., M.D., M.P.H., F.A.C.P.

  3. dlseltzer said,

    From a reader:

    Thank you for this! So many times have I seen periods used in degrees!

  4. seltzer said,

    A reader wrote:

    As to periods in degrees, I believe that the absence of periods in degrees is JAMA-usage, and not widely observed elsewhere. In fact, the NEJM uses periods in degrees! Certainly in the legal profession, when people use degrees after their names (which is rare because lawyers, unlike doctors, are not pompous), they use J.D., not JD.

  5. felicia said,

    Underlining can be aesthetic. Just look at John Hancock’s signature on the Declaration of Independence. J

  6. Sharon said,

    Hello. If this blog and/or something like it regarding language usage tips is still being used or updated, I would certainly be interested in receiving the current information.
    By the way, the reason I found this is because I was looking up the use of periods in acronyms. There are people in my office who put periods all over the place when we write narratives, calendar entries, weekly logs, etc. And are not willing to give them up, thereby making the life of the data entry person or the typist easier. We have one company we deal with often which has a seven-letter acronym. And she wants periods between the letters each and every time it’s written.

  7. Frankie said,

    Dear Ms Seltzer,
    can I just add that in British English we use Mr, Mrs, Miss and Dr (although we do use co. and etc.).

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: