Summary

Make sure that you include the app name, version and technical support contact info within your app (or your next update)

The Fine Print

Section 5.6 says:

An application must include the application name, version information, and technical support contact information that are easily discoverable. 

But my app was improved without this?

This was a late introduction into the certification guide (a couple of weeks before launch) so it hasn't been enforced up till now. That said, it's now been long enough since release for everyone to be able to have time to add the information so expect to see apps failing if you forget to include this information.

How do I do this?

Well, that's the easy part, simply include an About page or Contact Us page. For contact you can send them to a forum link:

WebBrowserTask browser = new WebBrowserTask();
browser.URL = "http://somepublisher/forum";
browser.Show();

Or an email address:

EmailComposeTask emailComposeTask = new EmailComposeTask();
emailComposeTask.To = "Publisher <feedback@publisher.com>";
emailComposeTask.Subject = "Feedback About [Some App]";
emailComposeTask.Body = "";
emailComposeTask.Show();

When using tasks don't forget to wrap it in a try/catch statement.