Why mantain this two similar configuration possibility
in this case
<Module>
<name>Test</name>
<description>Test description </description>
<item>2,5,8</item>
<Module>
<item>
<id>2</id>
<type>MODS</type>
<category>Folder</category>
<name>Test</name>
<destination></destination>
<required>0</required>
<requirements></requirements>
</item>
the user see one module; the program install 3 item
in this case
<Module>
<name>Test1</name>
<description>Test description </description>
<item>2</item>
<Module>
<Module>
<name>Test2</name>
<description>Test description </description>
<item>5</item>
<Module>
<item>
<id>2</id>
<type>MODS</type>
<category>Folder</category>
<name>Test</name>
<destination></destination>
<required>0</required>
<requirements>5,8</requirements>
</item>
<item>
<id>5</id>
<type>MODS</type>
<category>Folder</category>
<name>Test</name>
<destination></destination>
<required>0</required>
<requirements></requirements>
</item>
the user see 2 module, selecting module Test1 also select module Test2 (deselecting Test2 also deselect Test1); the program install item 2,5 and 8
If 8 is not a module, insert it into module item or in item requirements is the same; if both inserted, double installation of that item (not a problem, only a loss of time)!
[edit] In the second case, the user can select and install only Test2 
