Handling of Identical Inventory During a Project Import
During a project import, an inventory item in the source project is considered identical to an inventory item in the target project if both items are associated with the same unique combination of component-version-license (CVL). By default, identical inventory is reconciled during the import by overriding all fields in the target inventory item with information from the import data file. In cases where the source inventory item has empty fields, the data in the target inventory item will be left as is (that is, will not be removed).
However, Code Insight does provide the option to append the contents of notes fields in the import data file to target inventory. See Options for Handling Inventory Notes and Custom Fields for details.