On the whole, "JK" is supposed to be right for children to be used in their online chats. It is harmless slang and means "just kidding." Parents should teach their children how to put it to effective use. Joking too much could hurt someone. Kids should also understand when a person is being serious or joking. Generally, "JK" is a good fun word to add amusement when talking with the right amount of usage.
Most importantly, it should be understood and learned by children so that they can apply it responsibly.
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