Rephrasing to avoid single instance of "long exchange"

draft-ietf-core-groupcomm-bis.md

@@ -537,7 +537,7 @@ When this happens, it is up to the specific client implementation to decide at w
 
 The application itself can be in a good position to decide what to do, depending on the available context information. For instance, it might accept and process all the responses from the same server, even if they are not Observe notifications (i.e., they do not include an Observe option). Alternatively, the application might accept and process only one of those responses, such as the one that is deemed to be the most recent one from that server, e.g., when this can trigger a change of state within the application.
 
-As part of a long exchange between the client and any of the servers in the CoAP group, the responses considered above are examples of the more general concept elaborated in {{Section 2 of I-D.bormann-core-responses}}.
+As part of a message exchange between the client and any of the servers in the CoAP group, the multiple responses considered above are examples of the more general concept elaborated in {{Section 2 of I-D.bormann-core-responses}}.
 
 ## Caching ## {#sec-caching}