During a general tidy-up at the Aero Club a couple of weekends back, we discovered this old [out of date!] page called "Ground To Air Emergency Visual Signalling Code", published by the "Civil Aviation Administration".
Before anyone asks, this is well out of date, but good for a laugh! I especially like the symbol for "Require Firearms and Ammunition"!!! I still can't quite understand what use that might be in civil aviation... ? :-)