title: DisplayFormat.DataFormatString for a phone number or social security number
body: <p>Is there a way I can use the <code>DisplayFormat</code> attribute on a view model property to apply a <code>DataFormatString</code> format for a social security number or a phone number?  I know I could do this with javascript, but would prefer to have the model handle it, if possible.</p>
  
  <pre><code>[DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "???????")]
  public string Ssn { get; set; }
  </code></pre>