Variable: abbreviated-home-dir
abbreviated-home-dir is a variable defined in files.el.gz.
Value
"\\`/root\\(/\\|\\'\\)"
Documentation
Regexp matching the user's homedir at the beginning of file name.
The value includes abbreviation according to directory-abbrev-alist.
Source Code
;; Defined in /usr/src/emacs/lisp/files.el.gz
(defvar abbreviated-home-dir nil
"Regexp matching the user's homedir at the beginning of file name.
The value includes abbreviation according to `directory-abbrev-alist'.")