rpcmessage: respCallerIds explained

src/rpcmessage.md

@@ -16,8 +16,8 @@ Attribute number | Attribute name      | Description
 8                | requestId           | Every RPC request must have unique number per client. Matching RPC response will have the same number. 
 9                | shvPath             | Path on which method will be called. 
 10               | method              | Name of called RPC method 
-11               | callerIds           | Internal attribute filled by broker to distinguish request from different clients with the same request ID.  
-13               | revCallerIds        | Internal attribute filled by broker to enable support for multi-part messages and tunneling.
+11               | callerIds           | Internal attribute filled by broker in request message to distinguish requests with the same request ID, but issued by different clients.  
+13               | respCallerIds       | Internal attribute filled by broker in response message to enable support for multi-part messages and tunneling. https://github.com/silicon-heaven/libshv/wiki/multipart-messages
 14               | access              | Access granted by broker to called `shvPath` and `method` to current user. 
 16               | userId              | ID of user calling RPC method filled in by broker.
 17               | accessLevel         | Reserved, integer value, it will be used in next API version for chained brokers access capping