Handling instructions (HX) convey special instructions to message handling and delivering operators.
The instruction is inserted in the message preamble between the precedence and the station of origin.
Its use is optional with the originating stations, but once inserted is mandatory with all relaying stations.

HXB (Followed by number) Cancel message if not delivered within...hours of filing time;
service originating station.

HXC Report date and time of delivery (TOD) to originating station.

HXD Report to originating station the identity of station from which received, plus date and time.
Report identity of station to which relayed, plus date and time, or if delivered report date, time
and method of delivery.

HXE Delivering station get reply from addressee, originate message back.

HXF (Followed by number.) Hold delivery until...(date).

HXG Delivery by mail or landline toll call not required. If toll or other expense involved,
 cancel message and service originating station.