Clear film on digitizer. What is it?

I separated the digitizer from the top glass and was in the process of removing the LOCA. There i noticed a film underneath the adhesive just above the digitizer/LCD assembly. I recall seeing a video somewhere on YouTube, a tech removed this film but did not give any information to what it was. Now i come to you guys to help give insight to what this film is for. I removed the film and now my screen is extremely clean. I do believe that this may be the polarizer, but from what i can see in the searches on Google is that the film that i find in the results look "polarized" and the one that i removed is absolutely clear (except for the OCA).

What do you guys think