To allow overwriting the theme in the import file with another theme, or it will be merged between themes.
Overwrite: The theme in the import file overwrites any other theme under the same name in the knowledge base.
Incremental Integration: A merge is done between themes of both revisions, and the result is a theme that is a merger of both themes.
Default: Incremental Integration
In case of conflict between the two themes concerning class names, it can be solved using Class Conflicts Property.
Action: Import option
Import Dialog Options