Do the INS workers start checking on your application when your application priority date is current or before, as soon as they get your paperwork? I'am asking because I see some posters signatures, on which they sent their package like in October, and by November, USCIS is requesting evidence from them. Like they're working on their case or something. So my questions is, Does INS stark working on your paperwork as soon as they get it? if that's the case, what is the point of a priority date?