My Alnico V Nailbomb and Warpig pickups have the same hand-written note on them. I assume these appear on all alnico pickups that have a ceramic option.
I imagine that the only case where you might find a Nailbomb or Warpig with a card that doesn't have this would be if it was one of the early ones produced before the ceramic magnets were a regular production item (rather than a custom fitment).
So, yes, this is good evidence that you have the alnico version rather than the ceramic. Did you buy it second-hand?