Ok, I did a little googling and found an answer. It looks like that is the standard translated text the Italians use for the "fork adjustment" in all their owner manuals. Or it could be a typo. Just think of it as a standard preload adjuster: full clockwise is max preload or a stiffer spring, full counter clockwise is min preload.
You would be correct. Of course I didn't realize what I typed until after it was too late to change it.Without wishing to be a pedant, preload won't give you a 'stiffer spring', it doesn't effect spring rate.