diff --git a/Node-documentation-guide.md b/Node-documentation-guide.md
index c25fcbe..e70e5d9 100644
--- a/Node-documentation-guide.md
+++ b/Node-documentation-guide.md
@@ -16,7 +16,7 @@ After the short description the documentation should give a fuller description o
 All configuration parameters should be described fully, including any incoming msg properties that override the default configuration.  
 
 ###Output  
-Document all outgoing properties that are set of modified by the node.
+Document all outgoing properties that are set or modified by the node.
 
 ###External reference  
 If the node is an interface for an external system or protocol then a link to the relevant home page or similar site should be provided.
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