Here we would like to draw your attention to SKPR13 transaction code in SAP. As we know it is being used in the SAP BC-SRV (Basis Services / Communication Interfaces in Basis) component which is coming under BC module (BASIS).SKPR13 is a transaction code used for File Name Extensions in SAP.
It comes under the package SDOK.
Transaction SKPR13 technical data table
|Purpose||File Name Extensions|