WHat does this mean?
Don't forget to use BWK as password, or your shares will be lost !!!
What will be the difference if I set -p BWK? No the -p is empty in my batch file.
I don't think it's actually needed for the poolofd32th pool. Some pools mine multiple coins on the same port, for example look at the x11, scrypt and quark rows in the table on poolofd32th there is more than 1 coin for each of those. So if you only want a particular coin out of the three x11 coins the pool is currently mining, then it's not enough to just specify -a x11 and the port in your miner batch file you'll also want to somehow notify the pool about the actual coin you're after. That is done with the "-p c=BWK" parameter.
As of right now though, poolofd32th is only mining one NIST5 coin, which is Bulwark. So it's not really required. But if the pool operator will later decide to mine another NIST5 coin on the same port, then that "-p c=BWK" will be required. So you might want to add this option now just to be safe in the future.