query-capitalize-upper-word.el

;;; The command is extracted from interactively query-replace-regexp:
;;; 1) M-C-% or "M-x query-replace-regexp"
;;; 2) Search: \<[[:upper:]]\{2,\}\>
;;; 3) Replace: \,(capitalize \&)
;;; 4) After finish the query replace, use C-x M-: to extract the command
(defun iy/query-capitalize-upper-word ()
  "Capitalize the word with all letters in upcase"
  (interactive)
  (query-replace-regexp
   "\\<[[:upper:]]\\{2,\\}\\>"
   (quote (replace-eval-replacement
           replace-quote (capitalize (match-string 0))))
   nil
   (if (and transient-mark-mode mark-active)
       (region-beginning))
   (if (and transient-mark-mode mark-active)
       (region-end))))