diff --git a/appvm/qubes.Filecopy.policy b/appvm/qubes.Filecopy.policy
index 6ecc534d..0a0d7352 100644
--- a/appvm/qubes.Filecopy.policy
+++ b/appvm/qubes.Filecopy.policy
@@ -1 +1,6 @@
+## Note that policy parsing stops at the first match,
+## so adding anything below "$anyvm $anyvm action" line will have no effect
+
+## Please use a single # to start your custom comments
+
 $anyvm	$anyvm	ask,user=root
diff --git a/appvm/qubes.OpenInVM.policy b/appvm/qubes.OpenInVM.policy
index 7c9ccb41..41217337 100644
--- a/appvm/qubes.OpenInVM.policy
+++ b/appvm/qubes.OpenInVM.policy
@@ -1,2 +1,7 @@
+## Note that policy parsing stops at the first match,
+## so adding anything below "$anyvm $anyvm action" line will have no effect
+
+## Please use a single # to start your custom comments
+
 $anyvm	$dispvm	allow
 $anyvm	$anyvm	ask
diff --git a/dom0/aux-tools/qubes.ReceiveUpdates.policy b/dom0/aux-tools/qubes.ReceiveUpdates.policy
index 611f006d..0f00b0b6 100644
--- a/dom0/aux-tools/qubes.ReceiveUpdates.policy
+++ b/dom0/aux-tools/qubes.ReceiveUpdates.policy
@@ -1 +1,6 @@
+## Note that policy parsing stops at the first match,
+## so adding anything below "$anyvm $anyvm action" line will have no effect
+
+## Please use a single # to start your custom comments
+
 $anyvm	dom0	allow
diff --git a/dom0/qubes.SyncAppMenus.policy b/dom0/qubes.SyncAppMenus.policy
index 611f006d..0f00b0b6 100644
--- a/dom0/qubes.SyncAppMenus.policy
+++ b/dom0/qubes.SyncAppMenus.policy
@@ -1 +1,6 @@
+## Note that policy parsing stops at the first match,
+## so adding anything below "$anyvm $anyvm action" line will have no effect
+
+## Please use a single # to start your custom comments
+
 $anyvm	dom0	allow
diff --git a/qrexec/qrexec_policy b/qrexec/qrexec_policy
index c44ca258..52632abf 100755
--- a/qrexec/qrexec_policy
+++ b/qrexec/qrexec_policy
@@ -12,6 +12,10 @@ def line_to_dict(line):
     tokens=line.split()
     if len(tokens) < 3:
         return None
+
+    if tokens[0][0] == '#':
+        return None  
+
     dict={}
     dict['source']=tokens[0]
     dict['dest']=tokens[1]