When using Copy if newer (incremental) as your copy method with Copy Content, ShareGate Migrate matches your items at the source with the items at the destination to determine what items to copy.

If you migrate a library's content with Copy if newer (incremental), ShareGate Migrate compares the source documents to the destination documents based on the source's file paths.

If a document was moved to another folder in the destination and an incremental migration is done, ShareGate Migrate is not able to see the file was moved. In this scenario, the file will be copied as a new file in the original location because the application does not see that the file exists in another folder.

If you migrate a list and and get the error "This item has not been copied since there are multiple matching items at the destination. Please review your key properties", you can change your key properties to select properties with unique values on every list item. This way, the application can properly identify your list items between the source and the destination.

You can find more about key properties in the Key properties article.