title: How to choose --prefix for git svn clone
body: <p>When I try <code>git-svn clone</code>, I get a warning:</p>
  
  <blockquote>
  <pre><code>WARNING: --prefix is not given, defaulting to empty prefix.
       This is probably not what you want! In order to stay compatible
       with regular remote-tracking refs, provide a prefix like
       --prefix=origin/ (remember the trailing slash), which will cause
       the SVN-tracking refs to be placed at refs/remotes/origin/*.
  </code></pre>
  </blockquote>
  
  <p><code>--prefix</code> is not mentioned in the git book <a href="https://git-scm.com/book/en/v2/Git-and-Other-Systems-Migrating-to-Git" rel="nofollow">chapter on <code>git-svn</code></a>.
  Various web pages recommend using <code>--prefix</code> (<a href="http://blog.tfnico.com/2013/08/always-use-git-svn-with-prefix.html" rel="nofollow">tfnico</a>, <a href="https://objectpartners.com/2014/02/04/getting-started-with-git-svn/" rel="nofollow">objectparters</a>), but fail to explain what I should call it. Is it just an arbitrary name, or should it match something in the SVN repository?</p>