I've a doubt to get clear !!

Those lines mean that a filter is applied to the routing process.

Look at this example:

R1 have OSPF configured and we apply the distribute-list 1 in the inbound direction, so the show ip protocol output will change to:

R1(config-router)#distribute-list 1 in

R1#show ip protocols

Routing Protocol is "ospf 1"

  Outgoing update filter list for all interfaces is not set

  Incoming update filter list for all interfaces is 1

<output ommited>

Elvin

distribute-lists are more CCNP topic but you are welcome to read on.