Chaos Gate Requirements

The valid teleportation locations that observe this Law all do have three Key Word requirements already, but until any Contestant knows what a Chaos Gate is, the Law won't be put into practice.
Nexus has revealed some of the Key Words, only saying what one of them is per Hint. The Contestants have been sharing information, right?
Law originates from .hack//sign since that's how they get in between Fields (outside areas, dungeons, etc) and Root Towns (towns).