Clarified how a group name can be included in a URI path for reverse …

…proxies; removed reference to URI templates for reverse proxies.

draft-ietf-core-groupcomm-bis.md

@@ -623,7 +623,9 @@ CoAP enables the use of a reverse-proxy, as an endpoint that stands in for one o
 
 In a group communication scenario, a reverse-proxy can rely on its configuration and/or on information in a request from a client, in order to determine that a group request has to be sent to servers in a CoAP group, over a one-to-many transport such as IP/UDP multicast.
 
-For example, specific resources on the reverse-proxy could be allocated, each to a specific application group and/or CoAP group. Or alternatively, the application group and/or CoAP group in question could be encoded as URI path segments. The URI path encodings for a reverse-proxy may also use a URI mapping template as described in {{Section 5.4 of RFC8075}}.
+One typical implementation is to allocate specific resources on the reverse-proxy to application groups. A client can then select the application group, and group resource to access, using the URI path in its group request. For example, a request to /proxy/APPNAME/res1 could give access to resource /res1 in the application group APPNAME. In this example the proxy automatically selects the associated CoAP group.
+
+In general, using the URI path to select application group and/or CoAP group is an efficient way to access a reverse proxy. Other methods are possible, such as using the URI authority component: this requires configuration of more elements on the reverse proxy like multiple virtual servers and/or multiple IP addresses and/or multiple port numbers.
 
 The reverse-proxy practically stands in for a CoAP group, thus preventing the client from reaching the group as a whole with a single group request directly addressed to that group (e.g., via multicast). In addition to that, the reverse-proxy may also stand in for each of the individual servers in the CoAP group (e.g., if acting as firewall), thus also preventing the client from individually reaching any server in the group with a unicast request directly addressed to that server.
 
@@ -1722,6 +1724,8 @@ Finally, {{sec-proxy-forward}} refers to {{RFC8075}} for the operation of HTTP-t
 
 ## Version -11 to -12 ## {#sec-11-12}
 
+* Clarified how a group name can be included in a URI path for reverse proxies; removed reference to URI templates for reverse proxies.
+
 * Clarified the issue of identical ETags from multiple servers and added strategies to cope with this. Removed recommendation to not use such duplicate ETags.
 
 * Simplified section on application group naming using URI authority and corresponding appendix examples; declaring new Option solution out of scope.