whether you follow SSC or RACK, the most important thing is that you never submit to another until you are happy that your limits will be honoured. Some will say that a slave has no limits! This is total BS. Everyone has limits! Would you f*ck your own 10 y.o son or daughter because you are a slave and that was your Master's order?
To become a slave and have 'no limits' means that you have established knowledge and trust in your partner to know that while you may be pushed, you will never be pushed to the extent of overstepping boundaries.
If its going too far, you need to talk/communicate ... if that just gets a "you a slave... do as I say", you are in the wrong relationship.
I guess I am just saying the same as the others above - just puting it a different way.
Brosco