BT     Break in text. Used as a separator between thoughts or a pause. Also something good to send when your mind goes blank or you are talking to someone in your shack, etc.
WX IS CLDY BT AGE HR IS ….
AR     End of message. Use when you are through sending info, and turning it over to the station you are working. Also used when answering a CQ.
blah, blah, blah, hw? AR KB3BFQ DE K3WWP K. – or – To answer KB3BFQ’s CQ, KB3BFQ DE K3WWP AR
K     Go ahead. Used to tell the station you are working you expect him to transmit now. Use after a CQ to invite someone to answer you. Do not use K after you answer someone’s CQ since you don’t know he is going to answer you, use AR.
HW? AR KB3BFQ DE K3WWP K