4x4 is for people new to 4x4 vehicles - "What does this lever do?".
Advanced 4x4 is for people with 4x4 experience - "How would I get over this obstacle?"
Performance is for things that provide more performance - "Will this coffee can make my Xterra faster?"
Drivetrain is for stock drivetrain parts - "Why are this six little balls lying next to my front wheel?"
A locker thread would go where it's most useful.
"What's a locker?" - 4x4
"How do I hook up the plumbing on my ARB Air Locker?" - Advanced 4x4
It's all pretty straight forward...
![laugh laugh](/forums/images/graemlins/default/laugh.gif)