The WITNESS_INTERFACE_LIST structure specifies the list of interfaces available for witness registration. 

 typedef struct _WITNESS_INTERFACE_LIST {
     UINT NumberOfInterfaces;
     [size_is(NumberOfInterfaces)] [unique] PWITNESS_INTERFACE_INFO InterfaceInfo;
 } WITNESS_INTERFACE_LIST, *PWITNESS_INTERFACE_LIST;
  
  

NumberOfInterfaces:  The number of WITNESS_INTERFACE_INFO structures in InterfaceInfo.

InterfaceInfo:  Contains an array of WITNESS_INTERFACE_INFO structures, as specified in section 2.2.2.5.