I have just committed a change to CVS, that treats xowiki page names in wiki links starting with a "/" like external links.
If one writes e.g. [[/xowiki]] this will turn into a link to the same site with that value. This is not only useful for interwiki links, but as well to links to pages from the same site without requiring "
http://hostname/";
However, this has the consequence that page names are not allowed to start with a "/" (seems anyhow a good idea)
For now, this links are marked with the same symbol as external links (one is leaving an wiki instance). If someone has a nice symbol for this interwiki/samesite links, please let me know.