Skill Relations : raw talent and when knowledge overlaps.
Master Skill Bonuses : related skills are easier to learn as you already know the basics.
Skill Talents : high skill ranks can have other benefits too.
Skill Defaults List : find out which skills are related
Alternative Perception Rules : Can one skill do it all? New rules for perception as a skill base plus a number of skills re-thought and how to switch over from the old to the new.