Comment:

There needs to be a general-purpose extension to capture the "value set" from which a coding was drawn. This is important for the QRDA Category I use case, as all the resources need to indicate for each coding what value set they are satisfying, but it could also be used by decision support as a way to communicate that the coding for a particular resource should come from a given value set.

Summary:

"sourceValueSet" extension for Coding