Emacs Lisp Toothpick Syndrome
Here's a real world one.
For explanation of the above one, see
[• backslashitis By wasamasa. At http://emacshorrors.com/posts/backslashitis.html , Accessed on 2016-02-03 ]
thanks to reddit discussion. https://www.reddit.com/r/emacs/comments/43zov2/todays_xkcd_reminds_me_of_emacs_lisp_regexes/
For explanation of backslash in elisp regex, see Emacs Lisp: Regex Tutorial
See also: Problems of Symbol Congestion in Computer Languages; ASCII Jam vs Unicode