Does anyone have a prada with nothing on the zipper? I just returned a bag to a Resale shop in LA because of this, as I think it is fake. They are going to refund, but say the seller insists the bag is authentic and is having it authenticated. They say this seller often sells high end bags through them and this has never been a problem.
^Just looked at one of my duffles (an entry-level large nylon duffle bought from the Prada outlet in Italy) and one of the zippers is YKK, but the other has NO marking that I can see. So, to answer your question, YES, Prada will sometimes have bags with zippers with NO markings.
Geesh, I wish Prada would do like LV or Hermes and be consistent with their zippers. It makes it so hard to tell what's what! But, Prada is one of the worst about outsourcing their manufacturing, so I guess it's just to be expected that the hardware and details won't be totally consistent.