title: Remove json field in ASP MVC WebApi Action Method
body: <p>I have a controller that accepts a model UpdateProductCommand like this:</p>
  
  <pre><code>public IHttpActionResult UpdateProduct(UpdateProductCommand command)
  {
      command.AuditUserName = this.RequestContext.Principal.Identity.Name;
      // ....
  }
  </code></pre>
  
  <p>For security issues, the <code>AuditUserName</code> field should never be set outside (from the API call). </p>
  
  <p>How can I remove (or truncate) the value of this field from JSON request?</p>