How the param `layout: false` works in the render function

The following is a code snippet from the newly generated Phoenix project:

defmodule HelloWeb.PageController do
  use HelloWeb, :controller

  def home(conn, _params) do
    # The home page is often custom made,
    # so skip the default app layout.
    render(conn, :home, layout: false)
  end
end

I’m wondering about how the param layout: false works. It seems there are some predefined options, so I looked at the documentation for the render function and Plug.Conn, but I didn’t see anything relevant. Where did I go wrong ?

It seems to be missing in documentation indeed.

I think so.