I am using Emacs to write a long thesis in LaTeX. I have no regrets, so far (about the Emacs/LaTeX combination, that is). One of the last things I need to do before I can submit the darn thing is to compile a list of abbreviations. Of course, I should have kept tabs on the abbrevs I have used, but I haven't.

Now, is there some way to employ the power of Emacs to find abbreviations, ideally even to have them displayed in a separate buffer?

Obviously, this is a good use-case for regular expressions. Abbreviations could be defined as at least three consecutive upper case letters delimited by whitespace. My regex skills are very limited, though. I tried to search (isearch.el) for \b[A-Z]{2,4}\b, but all I got was Failing regexp Isearch.

What am I doing wrong? Maybe someone has already written a useful script for this purpose. (Couldn't find anything on (M)ELPA.)

  • 2
    \b[A-Z]\{2,4\}\b will do; you need to escape the brackets.
    – Juancho
    Jul 10, 2015 at 16:37
  • 1
    You can use occur to get a browseable list of matches.
    – Juancho
    Jul 10, 2015 at 16:37
  • 1
    For at least 3 consecutive upper case letters, you need \b[A-Z]\{3,\}\b Jul 10, 2015 at 18:07

2 Answers 2


Here's a couple of functions that will do what you want (make sure to (require 'cl-lib) first). They will gather all the abbreviations of 3 capital letters or more, along with the point location that you first used them. They will then create a new buffer *Abbreviations* that will list them and their locations. (Despite the uncreative function names, they have nothing to do with Emacs' abbrev facility.)

Basically, evaluate these two functions and then M-x display-abbrevs.

(defun gather-abbrevs ()
  "Gather all abbreviations (3 or more capital letters) in the
buffer.  Return an alist of all of them and the point location of
their initial use."
  (let (case-fold-search abbrevs)
        (goto-char (point-min))
        (while (re-search-forward "\\b[A-Z]\\{3,\\}\\b" nil t)
          (push (list (match-string 0)
                      (- (point) (length (match-string 0))))
        (nreverse (cl-delete-duplicates abbrevs
                                        :key  #'car
                                        :test #'equal))))))

(defun display-abbrevs ()
  "Gather all abbreviations (3 or more capital letters) in the
current buffer.  Display them and their initial point locations
in the *Abbreviations* buffer."
  (let ((buf (buffer-name))
        (new (get-buffer-create "*Abbreviations*"))
        (abs (gather-abbrevs)))
    (with-current-buffer new
      (delete-region (point-min) (point-max))
      (insert (concat "Abbreviations in the <" buf "> buffer\n\n"))
      (insert "Abbrev.\t\tLocation\n")
      (cl-dolist (a abs)
        (insert (concat (car a) "\t\t"
                        (number-to-string (cadr a)) "\n")))
      (pop-to-buffer new))))

Note that I've only tested them very briefly, so there may be bugs.

  • It works! Thank you for this brilliant solution. You should put it on some repository, because it is a very useful tool for writers. Jul 14, 2015 at 10:29

If you are comfortable with occur, then try this:

M-x occur RET \b[A-Z]\{2,4\}\b

You can play with 2,4 values to adjust to your needs, perhaps different values for different parts of your thesis. Results are shown in a new buffer.

Since occur is available on default installations of Emacs, you don't have to add new libraries or dependencies.

  • +1: This solution has the advantage of being quick and easy to use. The main disadvantage is that it lists ALL lines with the abbreviations. However, if you use the abbreviations repeatedly throughout the text (which you probably do, or you wouldn't have bothered with an abbreviation in the first place), you'll get many, many more lines in the occur buffer than unique abbreviations. Your task would then be to go through the latter buffer and find the unique abbreviations, which could be error prone.
    – Dan
    Jul 10, 2015 at 20:32
  • Works like a charm. Thanks for explaining the useful occur and pointing out the correct syntax. Jul 14, 2015 at 10:32

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