diff --git a/docs/schemas/nwfilter.rng b/docs/schemas/nwfilter.rng
index 262e420106..95fa6b533a 100644
--- a/docs/schemas/nwfilter.rng
+++ b/docs/schemas/nwfilter.rng
@@ -24,6 +24,7 @@
                   <ref name="match-attribute"/>
                   <ref name="common-l2-attributes"/>
                   <ref name="mac-attributes"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -33,6 +34,7 @@
                   <ref name="match-attribute"/>
                   <ref name="common-l2-attributes"/>
                   <ref name="arp-attributes"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -42,6 +44,7 @@
                   <ref name="match-attribute"/>
                   <ref name="common-l2-attributes"/>
                   <ref name="arp-attributes"/> <!-- same as arp -->
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -54,6 +57,7 @@
                   <ref name="common-port-attributes"/>
                   <ref name="ip-attributes"/>
                   <ref name="dscp-attribute"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -65,6 +69,7 @@
                   <ref name="common-ipv6-attributes-p1"/>
                   <ref name="common-port-attributes"/>
                   <ref name="ip-attributes"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -76,6 +81,7 @@
                   <ref name="common-port-attributes"/>
                   <ref name="common-ip-attributes-p1"/>
                   <ref name="common-ip-attributes-p2"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -87,6 +93,7 @@
                   <ref name="common-port-attributes"/>
                   <ref name="common-ip-attributes-p1"/>
                   <ref name="common-ip-attributes-p2"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -98,6 +105,7 @@
                   <ref name="common-port-attributes"/>
                   <ref name="common-ip-attributes-p1"/>
                   <ref name="common-ip-attributes-p2"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -109,6 +117,7 @@
                   <ref name="common-ip-attributes-p1"/>
                   <ref name="common-ip-attributes-p2"/>
                   <ref name="icmp-attributes"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -119,6 +128,7 @@
                   <ref name="srcmac-attribute"/>
                   <ref name="common-ip-attributes-p1"/>
                   <ref name="common-ip-attributes-p2"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -129,6 +139,7 @@
                   <ref name="srcmac-attribute"/>
                   <ref name="common-ip-attributes-p1"/>
                   <ref name="common-ip-attributes-p2"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -139,6 +150,7 @@
                   <ref name="srcmac-attribute"/>
                   <ref name="common-ip-attributes-p1"/>
                   <ref name="common-ip-attributes-p2"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -149,6 +161,7 @@
                   <ref name="srcmac-attribute"/>
                   <ref name="common-ip-attributes-p1"/>
                   <ref name="common-ip-attributes-p2"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -159,6 +172,7 @@
                   <ref name="srcmac-attribute"/>
                   <ref name="common-ip-attributes-p1"/>
                   <ref name="common-ip-attributes-p2"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -170,6 +184,7 @@
                   <ref name="common-port-attributes"/>
                   <ref name="common-ipv6-attributes-p1"/>
                   <ref name="common-ipv6-attributes-p2"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -181,6 +196,7 @@
                   <ref name="common-port-attributes"/>
                   <ref name="common-ipv6-attributes-p1"/>
                   <ref name="common-ipv6-attributes-p2"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -192,6 +208,7 @@
                   <ref name="common-port-attributes"/>
                   <ref name="common-ipv6-attributes-p1"/>
                   <ref name="common-ipv6-attributes-p2"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -203,6 +220,7 @@
                   <ref name="common-ipv6-attributes-p1"/>
                   <ref name="common-ipv6-attributes-p2"/>
                   <ref name="icmp-attributes"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -213,6 +231,7 @@
                   <ref name="srcmac-attribute"/>
                   <ref name="common-ipv6-attributes-p1"/>
                   <ref name="common-ipv6-attributes-p2"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -223,6 +242,7 @@
                   <ref name="srcmac-attribute"/>
                   <ref name="common-ipv6-attributes-p1"/>
                   <ref name="common-ipv6-attributes-p2"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -233,6 +253,7 @@
                   <ref name="srcmac-attribute"/>
                   <ref name="common-ipv6-attributes-p1"/>
                   <ref name="common-ipv6-attributes-p2"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -243,6 +264,7 @@
                   <ref name="srcmac-attribute"/>
                   <ref name="common-ipv6-attributes-p1"/>
                   <ref name="common-ipv6-attributes-p2"/>
+                  <ref name="comment-attribute"/>
                 </element>
               </zeroOrMore>
             </optional>
@@ -571,6 +593,14 @@
     </optional>
   </define>
 
+  <define name="comment-attribute">
+    <optional>
+      <attribute name="comment">
+        <ref name="comment-type"/>
+      </attribute>
+    </optional>
+  </define>
+
   <!-- ################  type library ################ -->
 
   <define name="UUID">
@@ -826,4 +856,8 @@
       <param name="pattern">([Ff][Aa][Ll][Ss][Ee]|0)</param>
     </data>
   </define>
+
+  <define name='comment-type'>
+    <data type="string"/>
+  </define>
 </grammar>