simplify a bit, since the comments already exists in 071

tests/072-example2.vtc

@@ -14,33 +14,23 @@ varnish v1 -vcl+backend {
     sub vcl_miss { if (req.http.X-UA-Device) { set bereq.http.User-Agent = req.http.X-UA-Device; } }
     sub vcl_pass { if (req.http.X-UA-Device) { set bereq.http.User-Agent = req.http.X-UA-Device; } }
 
-    # so, this is a bit conterintuitive. The backend creates content based on the normalized User-Agent,
-    # but we use Vary on X-UA-Device so Varnish will use the same cached object for all U-As that map to
-    # the same X-UA-Device.
-    # If the backend does not mention in Vary that it has crafted special
-    # content based on the User-Agent (==X-UA-Device), add it.
-    # If your backend does set Vary: User-Agent, you may have to remove that here.
+    # standard Vary handling code from previous examples.
     sub vcl_fetch {
         if (req.http.X-UA-Device) {
             if (!beresp.http.Vary) { # no Vary at all
-                set beresp.http.Vary = "X-UA-Device"; 
+                set beresp.http.Vary = "X-UA-Device";
             } elseif (beresp.http.Vary !~ "X-UA-Device") { # add to existing Vary
-                set beresp.http.Vary = beresp.http.Vary + ", X-UA-Device"; 
-            } 
+                set beresp.http.Vary = beresp.http.Vary + ", X-UA-Device";
+            }
         }
-        # comment this out if you don't want the client to know your classification
         set beresp.http.X-UA-Device = req.http.X-UA-Device;
     }
-
-    # to keep any caches in the wild from serving wrong content to client #2 behind them, we need to
-    # transform the Vary on the way out.
     sub vcl_deliver {
         if ((req.http.X-UA-Device) && (resp.http.Vary)) {
             set resp.http.Vary = regsub(resp.http.Vary, "X-UA-Device", "User-Agent");
         }
     }
 
-
 } -start
 
 client c1 {