MIMETYPE (or similar) for JADN?

Are we going to (or have "we" already) registered JADN as a MIMETYPE
The question arises because if two systems are exchanging information about what messages should look like, it would be useful to pass the JADN.
I am imagining something like the mimetype application/ace-json (or the unofficially proposed application/json-schema)
means here is how to build a a loosely ltyped message
And s omething like the mimetype application/jadn
means here is some information modeled and strongly typesd stuff
tc