frame-auto-hide-function

frame-auto-hide-function is a variable defined in `window.el'.
Its value is

iconify-frame

• This variable may be risky if used as a file-local variable.

Documentation:
Function called to automatically hide frames.
The function is called with one argument - a frame.

Functions affected by this option are those that bury a buffer
shown in a separate frame like `quit-window' and `bury-buffer'.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 24.1 of Emacs.