Handling instructions (HX) are less used but quite useful in handling messages. They serve to convey any special instructions to handling and delivering operators. This "prosign," when used, 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. The following definitions apply:
* HXA--(Followed by number) Collect landline delivery authorized by addressee within...miles. (If no number, authorization is unlimited.)
* 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.
Example: NR 207 R HXA50 W4MLE 12...(etc.).
If more than one HX prosign is used, they can be combined if no numbers are to be inserted, otherwise the HX should be repeated thus: NR 207 R HXAC W4MLE...(etc.). On phone, use phonetics for the letter or letters following the HX, to ensure accuracy.
from ARRL website, www.arrl.org