Unclear role of diagram in Section 3 (discovering...)

The model/schema diagram in Section 3 does not have a title, is never referenced. It seems to be normative - isn't it? Then what should be required to conform to it should be clearly stated (provider OSLC service?). When doing so, I suspect several normative statements - like query 2, query 3 - would be superfluous, per the model definition itself. What is concerning is that the textual statements in that section, seem to imply that other parts of this model that do not have textual statements, are unimportant.