explain why most tags are masked out

src/tests/permutations.vtc

@@ -14,7 +14,6 @@ varnishtest "permutations of esion/esioff gzip/plain fetch/pass"
 #
 # backend: /O
 
-# XXX repeat count?
 server s1 -repeat 2 -keepalive {
 	rxreq
 	expect req.url == "/"
@@ -150,6 +149,8 @@ varnish v1 -arg "-a 127.0.0.1:0 -a self=${tmpdir}/v1.sock" \
 
 # this masks out most of the VSL to push the output size just under
 # the 1MB default varnishtest log buffer size
+#
+# To get the full output, comment these out and run varnishtest with -b 10m
 varnish v1 -cliok "param.set vsl_mask -RespHeader,-BerespHeader"
 varnish v1 -cliok "param.set vsl_mask -ReqHeader,-BereqHeader,-Timestamp"
 varnish v1 -cliok "param.set vsl_mask -ReqUnset,-BereqUnset"