I've got well over 3000 hours in various 737's, 200, 300, 500 and I don't have a type. In the U.S.A it used to be very common for F/O's on domestic only aircraft to fly as F/O without a type rating. You went through all the training that the PIC did you even took the same check ride you just didn't receive a type at the end. Things have now changed for the most part and most F/O's are getting typed as F/O's at most major airlines.