New Alterac Valley xml

Hello am in the process of making a new Alterac Valley because the current one is a big weird. This one only works for Alliance but I have come across some confusing stuff.

Here is a line taken from AlteracValley.xml

<Hotspot x="-536.6096" y="-168.8863" z="54.6953354" default="true" tlx="-493" tly="-107" brx="-590" bry="-220" name="Galvangar" />

It shows the X, Y and Z coordinates but what's that other stuff after? like tlx, tly, brx, bry?

 

bryx and bry are the top right corner and bottom left corner of a 'hotspot' eg. a flag. tlx and tly i assume are similar

 

How do I get them in order? Which one goes first top or bottom?

 

Just imagine a square around where you want it to cover.

TLX & TLY---------------
| ................................ |
|..................................|
________________BRX&BRY

 

thanks that helps