To add more relationship types, you just need to modify the relationships picklist. Click on your name in the upper right corner of ClientLook and go to "Setup". Click on "Custom fields"  Under "Property Fields" click on the "Edit" link next to "Relationship". 

Add your items by typing in the "Enter new picklist value" box, then clicking the "Add value to list" button. When you are done adding everything, be sure to click "Save this field" to save your changes.
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