About Preferences for Boolean Operations
Click > 
Options > to set preferences for Boolean operations. The preferences you set determine the default options in the Boolean Operations dialog box.
Options > to set preferences for Boolean operations. The preferences you set determine the default options in the Boolean Operations dialog box.• Default Boolean Feature (boolean_default_operation)—Sets the default Boolean operation.
◦ By Model Type—Determines the default feature by the type of model. In Assembly sets the default to Merge, in Part sets the default to Add Bodies.
◦ Add Bodies
◦ Merge
◦ Cut
◦ Intersect
• Associative placement (boolean_associative_placement)—Updates the Boolean feature according to the placement of the modifying component.
• Transfer References(boolean_transfer_refs)—Transfers all references from the modifying components to the resulting Boolean feature.
• Discard modifying components (boolean_discard_modifying)—Deletes the modifying components after a Boolean operation.
• Copy Datum planes (boolean_copy_datums)—Copies datum planes from the modifying component to the modified model as part of the Boolean operation.
• Copy Quilts (boolean_copy_quilts)—Copies quilts from the modifying component to the modified model as part of the Boolean operation.