title: Culture-aware string comparison for Umlaute
body: <p>I need to compare two strings in German language to check if they are equal and only differ in the use of umlaute. E.g. "Jörg" should be the same as "Joerg".</p>
  
  <p>So I tried:</p>
  
  <pre><code>var ci = new CultureInfo("de-DE");
  int compareResult = ci.CompareInfo.Compare("jörg", "joerg", CompareOptions.IgnoreNonSpace);
  </code></pre>
  
  <p>as well as</p>
  
  <pre><code>int compareResult = String.Compare("jörg", "joerg", true, ci);
  </code></pre>
  
  <p>(or are those two equal anyway?)</p>
  
  <p>However, this does not work and will return <code>1</code>. It is the same for all umlauts ö,ü and ä. If I compare <code>strasse</code>and <code>straße</code> in the same way, this does work and returns <code>0</code>?! </p>
  
  <p>Thanks for any ideas! This <a href="https://stackoverflow.com/a/13562495/1537195">post</a> suggests that mine should work.</p>