The General Rules are lowest priority that 404 Rules they will be applied when there is no other rules applied, look at the following screenshot
In this screen you do:
- Redirect all 404 webpages to homepage or to a specified page.
- Replace all broken images in your site with a default one (may be your logo).
- Redirect all 404 JS/CSS to default file.
- Redirect all unknown types 404 links to homepage or to a specified page.