text: Several Internet websites â '' such as BT 's Connected Earthâ '' assert that Kevin Mackenzie proposed - ) as a joke-marker in April 1979 , on the MsgGroup ARPANET mailing list .
simplified: Several Internet websites -- such as BT 's Connected Earth -- assert that Kevin Mackenzie proposed - ) as a joke-marker in April 1979 , on the MsgGroup ARPANET mailing list .