diff --git a/src/main/java/net/floodlightcontroller/core/IOF13Switch.java b/src/main/java/net/floodlightcontroller/core/IOF13Switch.java
index f5648af..81e9fea 100644
--- a/src/main/java/net/floodlightcontroller/core/IOF13Switch.java
+++ b/src/main/java/net/floodlightcontroller/core/IOF13Switch.java
@@ -169,15 +169,18 @@
     public void createTunnel(String tunnelId, List<String> route, NeighborSet ns);
 
     /**
-     * Create a group chain with the same label stack for a given set of ports
-     * in the neighborset. This can be used for a basic scenario of tunnel based
-     * policy routing.
+     * Create a group chain with the specified label stack for a given set of
+     * ports. This API can be used by user to create groups for a tunnel based
+     * policy routing scenario. NOTE: This API can not be used if a group to be
+     * created with different label stacks for each port in the given set of
+     * ports. Use XXX API for this purpose
      *
-     * @param labelStack list of router segment Ids to be pushed
-     * @param ns neighborSet to get to the first router in the labelStack. NOTE:
-     *        The edgeLabel inside the neighborSet is ignored and user should
-     *        explicitly push that label on to the labelStack that is passed as
-     *        first argument
+     * @param labelStack list of router segment Ids to be pushed. Can be empty.
+     *        labelStack is processed from left to right with leftmost
+     *        representing the outermost label and rightmost representing
+     *        innermost label to be pushed
+     * @param ports List of ports on this switch to get to the first router in
+     *        the labelStack
      * @return group identifier
      */
     public int createGroup(List<Integer> labelStack, List<PortNumber> ports);