Security in Bdsm.

Basic thing to know

   Safeword.
   Limits.
   Weak of sensitive zone for impact play.
   Check list.
   Tools.

Advance thing to know

   Gravity laws.
   Blood circulation
   Nervus system
   Advance calculation
   Force calculation by vector and angle
   [Circus rigging document]
   Knight's forensic pathology pdf
   [Black rose training guide.]
   [Rape prevention workshop.]