Hi, tourist here from /lit/

tl;dr: Does polaroid film without a number on the back exist? See pic related as an example of what I mean. Also, are there other surefire ways to tell between real and fake polaroid film?

I bought some polaroids a while ago by an artist I like via the web and I always sort of assumed they're likely to be fake - they were cheap anyways - but I just noticed some of the polaroids have a number on the back, while some do not. I dont know shit about polaroids, but I figured some of you might.

Thanks in advance photochads