When converting an existing blog to ikiwiki it would be useful to be able to preserve any existing UUIDs on posts, in order to avoid flooding aggregators.

Also, it should be possible to change the canonical URL of a post, i.e. the atom <link> (e.g. leaving a redirector behind) while keeping the same UUID (so that aggregators don't get confused).

Ideally UUIDs for blog posts should be chosen when the post is created, and frozen permanently by checking them in along with the content.

Perhaps ikiwiki's blogging functionality could be hooked up to the [[meta]] plugin, with a new meta keyword (uuid? feed-uuid? atom-uuid?) to achieve this.