Section 3.3.2 holds the following statement:

To enable consistent access to scanned narrative-only clinical reports, the Clinical Note Server SHALL expose these reports through both DiagnosticReport and DocumentReference by representing the same attachment URL using the corresponding elements listed below.² Exposing the content in this manner guarantees the client will receive all the clinical information available for a patient and can easily identify duplicate data.

What is a Clinical Note Server?

In section 2.2.1 it is indicated that US core can be used as profile only or profile+interaction. How does this section relate to these ways to support US Core?

The interaction support section (2.1.2.2) indicates that a server can choose what profiles it support which seems to contradict to this statement. 

Please define when do the requirements in this section apply and in what way they relate to section 2.2.1.