- On enwiki Special:RecentChangesLinked page enter the page title that will fetch some results with the default page settings - e.g. Apertium.
- Change the page tittle to de:Apertium - the suggested title will be displayed in the drop-down:
The results will not be displayed - a user might think that it's a correct result (which is not true).
- Reload the page - the warning explains that the pages titles with invalid interwiki prefix cannot be used here. The prefix de is not invalid, so the warning is misleading.
- Remove the prefix and observe that the results are displayed, but the warning does not go away:
Note: the steps can be repeated with entering an invalid page title - e.g. <<MediaWiki:Tag-foo-description>>, and then changing it to a valid title.