Hello sales2161
According to Cisco:
The Unicast RPF drop count tracks the number of drops at the interface. The Unicast RPF suppressed drop count tracks the number of packets that failed the Unicast RPF check but were forwarded because of the permit permission set up in the ACL.
So the suppressed drop count iterates by one whenever the uRPF condition is not met, but the packet is forwarded anyway because of a permit entry in the ACL.
This has been taken from the following Cisco documentation:
I hope this has been helpful!
Laz