At a bonus edition of Homebrew Website Club this weekend, we discussed how to delete a Webmention. We talked about both how to and how not to delete a Webmention, and the ins-and-outs of implementations between different servers. I thought I should write about this on my blog just in case anyone else would find the information helpful.
To delete a webmention, first remove a piece of content from your website. Then, ensure the page returns a 410 Gone HTTP status code. This status code indicates that a piece of content has been permanently removed a site. Then, resend a Webmention to the URL to which you originally sent the mention. If implemented, the Webmention receiver used by the site to which you sent the Webmention will acknowledge the 410 then delete the mention from their database. For example, webmention.io, a popular webmention receiver, has implemented deletion support.
If you want to update a Webmention, there is no need to delete it! Update your content then re-send your Webmention. If implemented, the target server will update their database to include the contents of your updated Webmention.