Example on VSphereBackupNFC


I have some queries regarding the vSphereBackupNFC. As my knowledge on ESX/VC features is pretty much less,
please bear with my dumb questions and help addressing them.

When can we use the vSphereBackupNFC enum value ?
As it was added as a tag over the VMKernel NIC (Host vNIC), do it works on both vDS and vStandard Switch ?
Is it applicable for Communication among Host to Host / Host to VCenter ?
Is it applicable for both Backup/Restore traffic, using nbd/nbdssl transport modes ?
If Yes, can a third party Backup Application can make use of this option ?
If the "VSphereBackupNFC" is configured on couple of VMKernel NICs, is there any order of preference ?
If the "VSphereBackupNFC" is already configured, Do the Backup application uses the same configuration by default?
Is there any manual setting avaialble to configure "VSphereBackupNFC" nictype?
If VSphereBackupNFC nictype is not available/unset, which vmKernel NIC will be used by default?

Please share a sample code