title: What is the difference between d:Source and d:DesignSource?
body: <p>There are two design-time attributes - <code>d:Source</code> and <code>d:DesignSource</code>. It seems both could be used for design data specification for CollectionViewSource:</p>
  
  <pre><code>&lt;CollectionViewSource x:Key="GrouppedCollection"
                        IsSourceGrouped="true"
                        Source="{Binding GroupedItems}"
                        d:Source="{Binding GroupedItems,
                                           Source={d:DesignInstance
                                                     Type=vm:MyViewModel,
                                                     IsDesignTimeCreatable=True}}" /&gt;
  </code></pre>
  
  <p><strong>OR</strong></p>
  
  <pre><code>&lt;CollectionViewSource x:Key="GrouppedCollection"
                        IsSourceGrouped="true"
                        Source="{Binding GroupedItems}"
                        d:DesignSource="{Binding GroupedItems,
                                                 Source={d:DesignInstance
                                                           Type=vm:MyViewModel,
                                                           IsDesignTimeCreatable=True}}" /&gt;
  </code></pre>
  
  <p>Is there any difference between them or they are just two names for the same thing?</p>