better PR entrance criteria per discussion

wt-2024.html

@@ -221,7 +221,7 @@ <h2>Success Criteria</h2>
 		  <a href="https://www.w3.org/Consortium/Process/#implementation-experience">at least two independent interoperable
 			  implementations</a> of every feature defined in the specification, where
 interoperability can be verified by passing open test suites, and two or
-more implementations interoperating with each other.</p>
+more implementations interoperating with each other. Interoperability between the independent implementations (that is, bidirectional data communication and transfer between the implementations facilitated by a relay server) should be demonstrated.</p>
 	  <p>There should be testing plans for each specification, starting from the earliest drafts.</p>
     <p>
       To promote interoperability, all changes made to specifications