Originally Posted by GUWonder

The way each country in the Schengen area runs electronic checks for a Schengen-entering/exiting person varies a lot, even as there are some common requirements for the checks.

The national differences in how the electronic checks are done and even in what is retained from a check can lead to some bizarre situations at passport control. Case in point being that Dutch passport control thought that I was some Baltic-area crime lord, and that was even as no other Schengen country’s passport control has ever made that ridiculous mistake. My travel docs are clean and my biographical info has almost nothing in common with that flagged Baltic mafia boss, and yet AMS passport control would slow me down and had no complete picture of my Schengen entry/exit/stay history. Never had that kind of ridiculous flagging issue at non-Dutch, Schengen ports of entry/exit when using the very same docs.