[wp-hackers] updating guid when changing permalinks

[Sam Angove]

On 7/5/06, John Joseph Bachir <jjb at ibiblio.org> wrote:
>
> I just realize that Lyceum does not update posts' GUIDs when changing the
> blog slug. This must be done when permalinks are update... but I can't
> seem to hunt down where WordPress takes care of this. Can someone point me
> in the right direction?

WordPress uses the permalink as the GUID, but any unique identifier
would do. A post's GUID should never change.

That it stops every post from being seen as "new" by RSS readers when
the permalink structure changes is the most practical reason why.