A frame has many parameters that control its appearance and behavior. Just what parameters a frame has depends on what display mechanism it uses.
Frame parameters exist mostly for the sake of graphical displays.
Most frame parameters have no effect when applied to a frame on a text
terminal; only the
buffer-predicate parameters do something special. If the
terminal supports colors, the parameters
display-type are also meaningful. If the terminal supports
frame transparency, the parameter
alpha is also meaningful.
By default, frame parameters are saved and restored by the desktop
library functions (see Desktop Save Mode) when the variable
desktop-restore-frames is non-
nil. It's the
responsibility of applications that their parameters are included in
frameset-persistent-filter-alist to avoid that they get
meaningless or even harmful values in restored sessions.