fwmark with port set to :0

[Leonard Soetedjo <Leonard@xxxxxxxxxx>]

Hi,

From the HOWTO, when using fwmark, I can set the port to be 0.  Is this 
correct?  Is it ok if I do that for a single port service such as telnet?

for example
iptables -t mangle -A PREROUTING -i eth0 -p tcp -s 0/0 -d VIP --dport telnet 
-j MARK --set-mark 1
ipvsadm -a -f 1 -r RS1:0 -g -w 1

Is the use of "0" not important? i.e. I can set to whatever I want?