Variable: frame-title-format
frame-title-format is a variable defined in xdisp.c.
Value
(multiple-frames "%b" ("" "%b - GNU Emacs at " system-name))
Documentation
Template for displaying the title bar of visible frames.
(Assuming the window manager supports this feature.)
This variable has the same structure as mode-line-format, except that
the %c, %C, and %l constructs are ignored. It is used only on frames for
which no explicit name has been set (see modify-frame-parameters).
Probably introduced at or before Emacs version 19.29.
Source Code
// Defined in /usr/src/emacs/src/xdisp.c
DEFVAR_LISP ("frame-title-format", Vframe_title_format,
doc: /* Template for displaying the title bar of visible frames.
\(Assuming the window manager supports this feature.)