RFC 6241 interpretation related to file:// URI

Question

The Netconf RFC 6241 provides an example like shown below.

 <rpc message-id="101"
      xmlns="urn:ietf:params:xml:ns:netconf:base:1.0">
   <copy-config>
     <target>
       <url>file://checkpoint.conf</url>
     </target>
     <source>
       <running/>
     </source>
   </copy-config>
 </rpc>

But it does not clearly explain how to interpret the URI file://checkpoint.conf. I see some implementations refers to this file under root '/', some refers to this file under current working directory. Some failed too in interpreting this. I see RFC 8089 does not clearly explain this relative pathing. Any one has idea on how to interpret this?

-Ram