edit rules

[Rodney Richison]

I'd like to make sure I've got this right.
To edit an existing rule like 20_dnsbl_tests.cf , I copy the rule to the 
/etc/spamassassin directory, then edit as I please like so..

header RCVD_IN_dnsbl_JAMM_com eval:check_rbl_txt('JAMM', 
'dnsbl.JAMMConsulting.com.')
describe RCVD_IN_dnsbl_JAMM_com Received via a relay in 
dnsbl.jammconsulting.com
tflags RCVD_IN_dnsbl_JAMM_com   net

Thank you