How do I block certain cards ?

It is possible to block certain cards from getting to your server, especially those fake cards or older cards:

Example:

You would like to block provider 0919 so to get the newer 093b cards from that provider.

In that case it would be necessary to make your C: line like this:

C: server.noip.com 12000 username password no { 0:0:2, 0919:0 }