A missed call is a telephone call that is deliberately terminated by the caller before being answered by its intended recipient, in order to communicate a pre-agreed message without paying the cost of a call. For example, a group of friends may agree that two missed calls in succession means "I am running late". The practice is common in South Asia, the Philippines and Africa.
The practice is against the law in South Korea. 
( z1 against :op ( z2 law ) :domain ( z3 practice ) :location ( z4 country :name ( z5 name :op "South" :op "Korea" ) ) )