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](/tips/howto_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](/ikiwiki/blog/) 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](/meta/plugin/), with a new meta keyword (uuid? feed-uuid? atom-uuid?) to achieve this.