Support data uri as resource content

[PatStLouis]

I would like to add support for data uri as resource content. The idea is for the content object to be:

{
   "id": "{dataUri}"
}

Nothing is preventing this as the content is arbitrary json, however I'm wondering if this special case could have a specific resourceType defined, by which the content is expected to only contain a data uri. This could be valuable to secure inline images or other inline data.

My current idea is that a resourceType registry could be defined as an annex to the specification for protected resourceTypes, and have DataURL as one of the registered resourceType.