This small module allows you to have a contextual filter argument apply only when there is no corresponding regular (exposed) filter value present. This is most common on initial page load. After that the contextual filters will silently retreat and let the exposed filter values as selected by the visitor do their thing without interfering. This means that you can take advantage of friendly URLs using contextual arguments instead of ugly and verbose query parameters. Put the URLs anywhere on your site, in emails and in newsletters to take visitors to tailored Views pages. Having arrived there, visitors may then further filter these pages to their heart's content using the View's regular filters you exposed. And they won't experience any odd behaviour.