A child of the main attrib <attrib> tag object.
<attrib Name="System" parent="anything" editable="0" visibleInEditor="1" default="" ></attrib>
There are 18 groups visible to the user in the UI. There is one totally hidden group, "Internal", containing 4 attributes.
The object contains a list of all the groups (the Internal group is described separately here).
See also—notes linking to here: