You know how to travel through the tunnels in the Arcos that are so prevalent in the year 2027. This gives you the implicit knowledge of any urban environment or structure. This lets you do certain things: where pipes and power lines are (average), how to locate secret access panels (difficult), where crawlways and ventilator ducts you can move safely through are (average), where alarms and monitors will be located (v. difficult), where (and how) power lines can be tapped into (difficult), and how to deactivate maintenance and guardian remotes (difficult).