Covens are groups of Wiccans/Pagans whom research/practice together. Generally they range from 3 to 13 people, but they can, and often do, contain more than 13 (13 is usually ideal). Covens can be same sex or mixed sex (meaning it can be only males, only females, or both males and females). The leader(s)of a coven is the high  priest(ess). Covens may practice sky clad (nude) or in whichever clothing preferred.