Otto Nove Due
For an aircraft that has a deceased person in the hold being repatriated, then Souls on Board will differ to Persons on Board.
The deceased is still a person but one could argue that their soul has departed. So in this case, Souls on Board is the correct term since if the correct Persons on Board figure was given, then the fire and rescue crew would be waiting a very long time at the bottom of the slide for the last 'Pax' to be accounted for!
Its a simple and long standing tradition and one that was drummed into me during my early PPL days.