Variable: dframe-attached-frame
dframe-attached-frame is a buffer-local variable defined in
dframe.el.gz.
Documentation
The frame which started a frame mode.
This is the frame from which all interesting activities will go for the mode using dframe.
Probably introduced at or before Emacs version 22.1.
Source Code
;; Defined in /usr/src/emacs/lisp/dframe.el.gz
(defvar-local dframe-attached-frame nil
"The frame which started a frame mode.
This is the frame from which all interesting activities will go
for the mode using dframe.")