Update for clarification

Make it clear which nodes in the cluster should have `http.enabled` set to `false`.

Closes #10305

docs/reference/modules/http.asciidoc

@@ -90,7 +90,11 @@ It also uses the common
 === Disable HTTP
 
 The http module can be completely disabled and not started by setting
-`http.enabled` to `false`. This make sense when creating non
-<<modules-node,data nodes>> which accept HTTP
-requests, and communicate with data nodes using the internal
-<<modules-transport,transport>>.
+`http.enabled` to `false`. Elasticsearch nodes (and Java clients) communicate
+internally using the <<modules-transport,transport interface>>, not HTTP. It
+might make  sense to disable the `http` layer entirely on nodes which are not
+meant to serve REST requests directly. For instance, you could disable HTTP on
+<<modules-node,data-only nodes>> if you also have
+<<modules-node,client nodes>> which are intended to serve all REST requests.
+Be aware, however, that you will not be able to send any REST requests (eg to
+retrieve node stats) directly to nodes which have HTTP disabled.