difference between undef and unknown

[David Shaw]

On Wed, Feb 02, 2005 at 09:23:47AM +0100, Nicolas Rachinsky wrote:
> Hallo,
> 
> can somebody tell me, what the difference between validity 'undef'
> and validity 'unknown' is?
> 
> Like here:
> pub   1024D/5B0358A2 1999-03-15 [expires: 2009-07-11]
> uid       [ unknown] Werner Koch <wk at gnupg.org>
> uid       [  undef ] Werner Koch
> uid       [  undef ] Werner Koch <wk at g10code.com>

Unknown means completely unknown.  The trust calculations have not yet
reached that key, the user ID is not signed by any key you have, etc.

Undefined means not enough information.  For example, if you have
marginals-needed set to 3 and only have 2 marginal signatures.

In practice, they are the same.  Either way, the user ID isn't valid
to encrypt to without a warning.

David