Re: region face has no background by default for new frames?

[Richard Stallman]

    Eval these: (face-background 'region) ==> "lightgoldenrod2"
                (face-background 'region t) ==> nil

    The latter seems wrong to me. If I read the doc string of
    `face-background' correctly, this would be saying that "the default
    [background] for face region (for new frames)" is nil. And that
    doesn't seem correct.

I think that the "default for new frames" does not include what is
specified in the defface.  It is what you set by calling
set-face-background and specifying t for the frame.  That overrides
what the defface says; but usually it isn't specified nowadays.

I tried to clarify the test in the Emacs Lisp manual.
Please take a look.