A query for the schema:about value of <https://en.wikipedia.org/wiki/Duck> shows that it's wd:Q3736439, but the Sitelinks section of this page says that it's wd:Q3. Am I misunderstanding something or does this example need to be corrected?
Topic on Talk:Wikibase/Indexing/RDF Dump Format
The example doesn't have correct values. It just has values to show how it's formatted. Examples usually have just random values as does this example.