Question about the GPL v3

[Ben Tilly]

On 8/16/07, Chris Travers <chris at metatrontech.com> wrote:
> Though this may be a typo, it seems incredibly unclear to me:
>
> Section 5d:
>
> d) If the work has interactive user interfaces, each must display
> Appropriate Legal Notices; however, if the Program has interactive
> interfaces that do not display Appropriate Legal Notices, your work need
> not make them do so.
>
> Am I right that this amounts to:
>
> "If the work has ineractive user interfaces, Appropriate Legal Notices
> may not be removed though they may be updated as appropriate?"

No.

It means that you cannot add user interfaces *without* appropriate
legal notices, nor may you remove them.  You are allowed to update
them, but they must remain appropriate legal notices.

> Here is my confusion.  THe first part says you must have these notices,
> but the second says that if you don't have these notices, you don't have to.

There is a contradiction, but I think that the intent is clear.  There
are a variety of ways in which you can wind up with GPL v3 code that
has interactive interfaces that don't display appropriate legal
notices.  (The most obvious is that existing non-GPLed code gets
GPLed, but nobody adds the notices.)  In those situations, you don't
have to go through all of the interfaces and immediately change them.
But new work has to be done right.

> Am I missing something obvious in the bounds of the license?  Is there
> any basis for any interpretation in the license or outside?

Just common sense.  Hopefully other people's common sense matches mine. :-)

Cheers,
Ben