- Look for an index page whose pagelist tag contains a language code (like <pagelist 36to533=it 566to576=it /> on https://en.wikisource.org/wiki/Index:The_Oxford_book_of_Italian_verse.djvu )
- Open a page which exists in the other language subdomain (e.g. https://en.wikisource.org/wiki/Page:The_Oxford_book_of_Italian_verse.djvu/114 )
I. Observed: the text is transcluded correctly (and the header says e.g. «This page does not need to be proofread. Its text comes from it.wikisource.org.»), but the page otherwise looks local.
II. Expected: for search engines purposes, the original page should be declared canonical, as file descriptions link the remote repository as canonical. <link rel="canonical" href="http://en.wikisource.org/wiki/Page:The_Oxford_book_of_Italian_verse.djvu/114" /> should be <link rel="canonical" href="http://it.wikisource.org/wiki/Pagina:The_Oxford_book_of_Italian_verse.djvu/114" />
The number of such pages indexed by Google seems limited: https://www.google.it/search?q=%22This+page+does+not+need+to+be+proofread.+Its+text+comes+from%22+site:wikisource.org&ie=utf-8&oe=utf-8&gws_rd=cr&ei=ct62VIkcwvlqlKCCqAY
It looks like the transcluded text is not indexed: https://webcache.googleusercontent.com/search?q=cache:MaIPZ183Tf4J:wikisource.org/wiki/Page:J%25C3%25B3zef_Gara_-_Zbi%25C3%25B3r_wierszy_o_wilamowskich_obrz%25C4%2599dach_i_obyczajach.pdf/11+&cd=1&hl=it&ct=clnk&gl=it