Have any women you've talked to mentioned such a system? Most women aren't very tech savvy, nor are they that proactive about their screening/vetting process...
I can see it being a thing in sororities but I cannot possibly imagine they keep a database of every guy in their entire city (unless its a small city/town, but even then, very unlikely). What seems more plausible is a maelstrom of disorganized gossip.
I'm mostly on the defensive because while this is a great explaination for the type of behavior OP described, it's rather disconcerting to imagine. If this is true, it's just another reason to ditch google, social media, and smartphones for good.