grumppa
SPAD also stands for Signal Passed At Danger on the railways, and therein lies the danger of so many abbreviations. I use the GN abbreviations only when their meaning is clear, e.g. DW (DH is also clear, but not one I would be expected to use).
This made my laugh grumpa. I wonder how many SPADs a SPAD passed while drive testing his eyes around Barnard Castle backalong, I'll get my coat ...