Clickable link might be already considered the bare minimum: needs legal checking.
Plus, bare URLs would be really ugly and long.

Anyway, this is the current HTML. Wouldn't it be enough to stick a "nofollow" to it?

<li id="footer-info-credits">This article is derived from the article <a class="external" href="http://wikitravel.org/wiki/en/index.php?title=Main_Page&amp;oldid=1900864">Main Page</a> on <a class="external" href="http://wikitravel.org/en/Main_Page">wikitravel.org/en</a> in its revision from 17:02, 21 July 2012 (UTC). There, it is published under the CC-by-sa 3.0 licence. More details and the full list of contributors can be found on the associated <a href="/w/index.php?title=Main_Page&amp;action=history" title="Main Page">history page</a>. (Wikitravel contributors are marked by the prefix WT-en).<br>
This article is derived from the article <a class="external" href="http://wikitravel.org/wiki/en/index.php?title=%27s-Hertogenbosch&amp;oldid=1720748">'s-Hertogenbosch</a> on <a class="external" href="http://wikitravel.org/en/Main_Page">wikitravel.org/en</a> in its revision from 23:01, 24 July 2011 (UTC). There, it is published under the CC-by-sa 3.0 licence. More details and the full list of contributors can be found on the associated <a href="/w/index.php?title=Main_Page&amp;action=history" title="Main Page">history page</a>. (Wikitravel contributors are marked by the prefix WT-en).</li>

Note that WikiTravel is already on https://meta.wikimedia.org/wiki/Interwiki_map ; I'll change those interwikis to point to en.voy instead soon unless someone objects, to bring our links to ourselves.

(In reply to comment #0)

The second link in these (Abondance, ś-Hertogenbosch) is spurious. It appears
on every page - the selection of spurious target merely changing from one
language version to another.

That's discussed on bug 41981 instead.

carlb613 wrote:

As far as I know, voy: is a valid interwiki to en.wikivoyage.org but wikivoyage: is not yet a valid prefix. To change these links will require that a robot be unleashed on every wiki with a {{wikitravel}} or {{wikitravelpar}} template to stick a {{wikivoyage}} template in its place with the voy: prefix. That hits a few odd languages like Cebuano or Romanian, as well as most of the majors (except Spanish and Japanese, which killed off the template years ago as IB spam)

There should be no links from anything WMF to a direct competitor's site; failing that, rel="nofollow" is a bare minimum. It will also be likely necessary at some point to start contacting owners of external (non-WMF, non-IB) sites who currently link to WT, politely explain the situation and ask they update these links.

Search engines tend to penalise duplicate content; to convince them that we are the main site and IB is the fork, we need as many links as possible pointing to wikivoyage.org and no links pointing to the old WT domain. Anything less allows IB to fragment the project as readers are directed in error to the abandoned fork, where staff are systematically censoring all information that the primary contributors have left for Wikivoyage.

(In reply to comment #3)

As far as I know, voy: is a valid interwiki to en.wikivoyage.org but
wikivoyage: is not yet a valid prefix.

I've done this now, although it will become live with a bit of delay depending on deployment schedules. https://meta.wikimedia.org/w/index.php?title=Interwiki_map&diff=4507874&oldid=4440403

To change these links will require that
a robot be unleashed on every wiki with a {{wikitravel}} or {{wikitravelpar}}
template to stick a {{wikivoyage}} template in its place with the voy: prefix.
That hits a few odd languages like Cebuano or Romanian, as well as most of the
majors (except Spanish and Japanese, which killed off the template years ago as
IB spam)

There should be no links from anything WMF to a direct competitor's site;
failing that, rel="nofollow" is a bare minimum. It will also be likely
necessary at some point to start contacting owners of external (non-WMF,
non-IB) sites who currently link to WT, politely explain the situation and ask
they update these links.

Search engines tend to penalise duplicate content; to convince them that we are
the main site and IB is the fork, we need as many links as possible pointing to
wikivoyage.org and no links pointing to the old WT domain. Anything less allows
IB to fragment the project as readers are directed in error to the abandoned
fork, where staff are systematically censoring all information that the primary
contributors have left for Wikivoyage.

All this doesn't belong to bugzilla, it should be discussed with the community.
Changed the summary to clarify what this bug is about.

carlb613 wrote:

The page footer is not controlled by the community, as far as I know, and the clickable link (which is missing rel="nofollow") *is* a bug which belongs here as it needs to be fixed.

(In reply to comment #5)

The page footer is not controlled by the community, as far as I know, and the
clickable link (which is missing rel="nofollow") *is* a bug which belongs here
as it needs to be fixed.

Of course, that's what I wrote in the bug summary...

• Bug 42029 has been marked as a duplicate of this bug. ***

https://gerrit.wikimedia.org/r/37057 Will fix the missing rel="nofollow" issue

Change merged. Note that it has not been backported, so it will not be live until the next release cycle (unless someone does so, which certainly won't happen until next week at the earliest).