There is a doc provided by SOE that explains most of this, its on your hard drive. Also be aware the bag window is hard coded to resize based on the number of slots in the actual bag. Changing the slot size means you'll have to use OnShow scripts to override SOE's autosizing. I stronly suggest you look at how other's have delt with this window.
<Page
The most basic UI building block, a retangle container of other objects that can have its own graphic style
Activated="true"
The page object's control state, usually used to trigger OnActivate and OnDeactivate script handlers. In this case there are no associated handlers
eq2usescomwndcontrols="true"
the page uses the standard EQ2 window setting controls
Location="489,26"
X and Y offset of the page's top left corner from its parent object's top left corner
MaximumSize="1024,1024"
The Page's max width and height
MinimumSize="20,20"
The Page's min width and height
Name="Bag"
object name for internal referencing of scripts, hardcoded functions and slash commands
ScrollExtent="35,50"
Size of the scrollable area within the page. When this matches the object's size, it doesn't scroll.
Size="35,50"
Width and height of the object
UserMovable="true"
The page can be moved ingame via mouse
>
<Page
AbsorbsInput="false"
Page is mouse clickable and blocks clicking objects behind it
BackgroundOpacity="1.000"
Transparency of the objects background graphics, 1.000 is fully opaque, 0.000 is fully transparent
Location="0,-1" Name="WC_Frame"
PackLocation="left,top"
location relationship to the parent object. In this case the top left corner of this page is anchored to the parent object. This setting determines how this object changes position when the parent object resizes. When not otherwise specified, the parent object's anchor is always left,top. Read SOE's doc for more info.
PackLocationProp="0000/0001,-001/0001"
Numerical distance of page's anchor to parent object's anchor. Speeds rendering but isn't required.
PackSize="absolute,absolute"
size relationship to the parent object. Determins how the child's size changes when the parent is resized. Absolute retains a fixed distance between parent and child edges, Proportional scales the child by the same percentage the parent object was scaled, Fixed means the child does not resize with the parent.
PackSizeProp="-005/0001,-002/0001"
Numerical settings for the child,parent size relashionship. Speeds rendering but is not required.