When a post is saved, we store a couple pieces of metadata:

• documentcloud documents stores all the shortcode attributes. I don't know what it's used for.
• wide_assets set to true|false to hint to the template that the post contains, well, wide assets. Several StateImpact sites respond to this hint according to Use oEmbed #16 (comment) and a Hangout conversation with @eyeseast

We have to make at least one change: both pieces of metadata are stored as hashes keyed by document slug. But now that we support notes – which are children of documents and thus whose URLs contain the document slug – we can have two embedded resources on the same post with the same hash key.

My recommendation:

1. Determine if documentcloud documents post meta is necessary (@eyeseast?) and if not, remove it
2. If resource is a note, include note ID as part of hash key to distinguish from documents.