diff --git a/README.md b/README.md
index beee659..87e0be5 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,8 @@
 
 ***IMPORTANT NOTE***  
 Starting with version 2.0, CCO IRIs are using a new namespace and have opaque local identifiers for all ontology elements.  
-See [here](https://github.com/CommonCoreOntology/CommonCoreOntologies/tree/develop/documentation/mappping-new-iris) for the mapping file.
+See [here](https://github.com/CommonCoreOntology/CommonCoreOntologies/tree/develop/documentation/mappping-new-iris) for the mapping file.  
+* At the momnent, CCO can not be accessed via the web using the ontology or element IRIs. Users will need to download the files and work with local copies. See [here](https://github.com/CommonCoreOntology/CommonCoreOntologies/issues/549).
 
 ## What is CCO?