This is a renewed feature. It is not entirely clear whether it ever worked properly. At any rate in its previous form it required the entry id and as such was fairly limited. The new feature allows updating by entry id but also by the content of a designated field. It remains the responsibility of the importer to use as identifier a field whose content is unique. If the content is not unique the first entry in the list with the specified content will get updated.

The UI consists of a checkbox in the view configuration form to enable the feature when Import is enabled. Then the import form will display a yes/no selector to select whether to use in a particular import.

When enabled and selected all entries for which an existing entry id cannot be found will be treated as new entries.