I remember when I worked communications centers in the USAF while supporting both US and NATO commands, we used a lot of Z signals and the occasional Q signals while servicing messages. You typically serviced messages when there was a problem with it's reception (even via data lines) like missing part 2 of 3. I recently stumbled upon this page. It has all the Q signals I do recall. http://www.wemsi.org/qsigs.html So QHZ and make sure your aren't QBN until QGN. And make sure you're QGW!