If you want to implement RNIF adapter you may want to have a look at the following blogs:
SAP Network Blog: Rosettanet / RNIF & XI - Breaking the Code
SAP Network Blog: RosettaNet and the role of RNIF in XI
SAP Network Blog: 'Close Encounters' with the Rosettanet STK
SAP Network Blog: Service-enabling RosettaNet business processes




