When do I provide the URL in the C4 parameter and why?

The C4 parameter should be populated with a hardcoded URL when the auto-populated URL in the C7 parameter does not represent the URL associated with the content the user is viewing. The most frequent cases for this are for dynamic content such as AJAX, Flash or a custom deployment of the comScore tag. In these cases, the C4 parameter should be populated manually with the full URL of the content being consumed by the end user, which is not necessarily the URL in the address bar of the browser. Please use the version of the comScore tag script and explicitly populate the values for each required parameter.