When a missing page returns a success status with empty or irrelevant content, the response can behave like a soft 404. A route should return its real content or a meaningful missing-page response.
Test one real URL and one impossible URL
Choose a known article, then add an obviously nonexistent path. Compare their status, title, and body. If both return the same homepage shell with success status, a catch-all route may be hiding the missing content. Do not add guessed paths to a sitemap just because the server returns 200 for them.
Make the content record decide the response
For a template-based site, look up the requested slug before rendering. Return the article only when the published record exists; otherwise return 404. Show a useful missing-page screen with links back to valid content. Test the deployed host because its rewrite behavior may differ from development.
Know the scanner’s boundary
SiteReadyFor.SI flags non-successful page fetches and sparse initial content, but it is not a complete soft-404 classifier. Its script route fallback may find a route-like string that is not a real public page. Verify these candidates against your content inventory when debugging discovery.