Shindig: what is the use of RpcToken in shindig

what is the use of RpcToken in shindig? I am creating Iframe ma开发者_JS百科nually , If I didn't set RpcToken then will it be a problem?

The rpcToken is used to secure the cross-domain communication between the iframe and the parent page. Note that this security check is skipped if the iframe is running on the same domain as the parent page.