In this article, you will learn how tags (keywords) are imported.
If the image files to be imported already contain keywords in the IPTC-IIM or XMP format (dc:subject), you can define how these are to be handled during the upload in the upper section of the Tag Manager: The options Import all and None should be self-explanatory. Import only known filters out the terms that have already been created as a tag.
The import data relevant here is usually comma-separated. If other characters are used as separators (e.g. a semicolon), these can also be created under Keyword separators.
If Import known only is active, smart tags are categorised as unknown by default and are not imported. This can be changed by activating the Import smart tags button.