On the SWG chart the asterisk at CYA of 60 says 'Not recommended' has me confused . To me it seems that if it is not recommended at 60 because it's too high then why are 70 and 80 okay? Also, why are there no listings for lower CYA levels. I'm sure some of you are laughing right now because I'm sure I've misread or misunderstood some part of that page (or all of it) and that's okay. But please help me to see what I missed.