I'm going to add this to the default rules with a score 0 so you can then just give it a score you want.
I also added spf_helo_nonesvn commit -m 'Added a default rule for SPF_NONE that is disabled with Score 0 for administrators to activate'
Sending rules/25_spf.cf Sending rules/50_scores.cf Transmitting file data .. Committed revision 1303613. Regards, KAM