For the convenience of practicing group sex occurred has its own system of notation of such varieties of sex. The coding system is very simple and consists of a combination of letters M (male) and F (female). For example, MZHM - it's sex with 2 men one woman MZHZH - a man with two women, MMM - three men, ZHZHZH - three women. Such a system makes it easy to describe any act of group sex. Also distributed Latinized version of the system, with the letters M and F (born male (male) and female (female), respectively), giving a combination of type MFF, MMF, MMM, FFF.