Transclude a page from another language or another project

Question

In Wikipedia, to copy the content of another page (called "transclusion"), you just need to add {{:SourcePageName}} in the destination page.

Is it possible to transclude a page from:

• Another language ? something like {{:fr:SamePageInFrench}}
• Another sister project (WikiBooks, WikiVersity) ? something like {{:wikibooks:PageInWikiBooks}}

Transclusion documentation: here

Answer 1

It's not possible. As specified in the documentation:

The general syntax for transclusion on Wikipedia is {{Namespace:Pagename}}, where Namespace:Pagename describes the title of a Wikipedia page.

The full list of namespaces is here, but it includes only pages on the English Wikipedia site, so neither in other languages or sister projects.