There might be some scenarios where you have methods that should only be invoked for AJAX requests. In those cases, you can use the AcceptAjaxAttribute to decorate those methods. This is an ActionMethodSelectorAttribute which overrides the IsValidForRequest and delegates all its work to the Request.IsAjaxRequest extension method.
When you’re not in an AJAX request, the IsAjaxRequest method returns false and you end up getting a 404 for that call. It’s really a simple attribute and you might want to recall how ActionMethodSelectorAttributes interact with the remaining elements of the platform.
And that’s all there is to say about this attribute. Stay tuned for more on the MVC framework.