Board Thread:Support Requests - Getting Technical/@comment-30561181-20170122102024/@comment-1757994-20170122150931

Only if the other wiki is Community Central.

The syntax is
 * for templates in Community Central's Template: space
 * for templates in the (Main) namespace
 * for templates in any other namespace, including the User: namespace

Transcluding interwiki templates is very "expensive" for the servers, however, which is why is disabled from every other wiki. It's not recommended unless there's a really good reason.