"Spanking is the act of striking the buttocks of another person to cause temporary pain without producing physical injury. It generally involves one person striking the buttocks of another person with an open hand. When an open hand is used, spanking is referred to in some countries as slapping or smacking. More severe forms of spanking, such as switching, paddling, belting, caning, whipping, and birching, involve the use of an implement instead of a hand.

Corporal punishment is most commonly used to discipline an infant, child, or teenager. It generally involves an adult – typically a parent, guardian, or teacher – striking the child's buttocks as punishment for unacceptable behavior. Historically, boys have tended to be more frequently spanked than girls.

Some countries have outlawed the spanking of children in every setting, but many allow it at least when administered by a parent or guardian. For the legal status of corporal punishment in different countries, see Corporal punishment in the home and School corporal punishment.

In some cultures, the spanking of a wife by her husband is considered an acceptable form of domestic discipline, though the practice is far less common than it used to be. In other contexts, the spanking of an adult can be considered a playful gesture during a social ritual or as a form of entertainment."  

in  http://en.wikipedia.org/wiki/Spanking  

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http://en.wikipedia.org/wiki/Erotic_spanking   

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