Section 7.1 should really be titled “Conformance clauses” (one for each target). Section 7.1.1 should be: “MQTT Server conformance clause”. And the Targets themselves should be functionally defined (what is their expected role and capability?) in a separate subsection before, outside the clause that assesses its conformance. And ideally early on in the spec ie.e outside the conformance section, so the reader understands what is meant even if only approximately, by “Server” and by “Client” in numerous statements in the spec body.