Variable: eww-use-browse-url
eww-use-browse-url is a customizable variable defined in eww.el.gz.
Value
"\\`mailto:"
Documentation
EWW will use browse-url when following links that match this regexp.
The action to be taken can be further customized via
browse-url-handlers.
This variable was added, or its default value changed, in Emacs 28.1.
Probably introduced at or before Emacs version 28.1.
Source Code
;; Defined in /usr/src/emacs/lisp/net/eww.el.gz
(defcustom eww-use-browse-url "\\`mailto:"
"EWW will use `browse-url' when following links that match this regexp.
The action to be taken can be further customized via
`browse-url-handlers'."
:version "28.1"
:type 'regexp)