Variable: tramp-host-regexp
tramp-host-regexp is a variable defined in tramp.el.gz.
Value
"[[:alnum:]_.%-]+"
Documentation
Regexp matching host names.
Source Code
;; Defined in /usr/src/emacs/lisp/net/tramp.el.gz
(defconst tramp-host-regexp "[[:alnum:]_.%-]+"
"Regexp matching host names.")