i think the first part to address is the Risk Awareness part. This means both parties being aware of all the risks involved in any activity that O/one is participating in. In my opinion, this includes both physical and emotional. Being aware, means studying the activities, learning about them, and negotiating how T/they plan to handle them. i have been told, this is the difference between just being safe and being aware. Apparently when O/one is simply being safe, T/they dont plan. In my own experience, this is just not true.
While i do agree the term sane leave a lot of leeway, i still think it is very important. Yes, what is sane to one person, may not be to another, but i think its the general concept of sane that has to be respected and used. So because of this, consensual comes into RACK. To alleviate some of the concern over what is really sane and what is not. Consensual implies being able to distinguish between fantasy and reality and dealing with the risk factors of both. Honestly in my humble opinion, one does the same thing with sane. i was very amused when i tried to find out the reasoning behind the word kink in RACK. Apparently, it was added so F/folks know what is being discussed, because no one knew what P/people were being safe, sane and consensual about.
i do admit this may seem a lil negative, and lacking in information. i had some trouble finding more in depth coverage and explanations of RACK. i am not sure if that is because it is not as widely practiced as SSC or just because there is none out there. As i do find more information, i will definitely make a point to add it though. Nonetheless, whichever principle, Y/you decide to use, simply remember, be careful and protect Y/yourself and Y/your partner. i really dont think W/we need to put a name on saftey.