Example: A server rule sets noindex for more content than intended
An X-Robots tag for download files can also hit public HTML pages due to an overly broad pattern. A change in the page content does not help, because the header is only added at the delivery. Similar conflicts arise with redirects and multiple security headers.
Finding the triggering point
Compare an affected HTML page, a real download file, and an unobtrusive resource. Read the full response headers with status code and forwarding sequence. Check the rules of application, web server, reverse proxy, and CDN individually as far as you have access to these levels.
Checking a limited fix
Limit the responsible rule to the intended paths or file types. Avoid multiple overlaid fixes that later overwrite the wrong header. Test security changes such as HSTS or CSP with their respective side effects, instead of just turning them on to remove an audit warning.
Check the result at the public address and at different content types. A successful HEAD test alone is not sufficient if GET responses run through another application path. Determine which level will be responsible for the header in the future.
Symptoms in the audit
- Error is not visible in HTML
- HEAD and GET provide different signals
- Only certain paths, hosts or file types are affected
Then they test the cause.
- 1. Check HTTP status, header and forwarding chain
- 2. Rules in . match htaccess, Nginx, CDN or hosting panel
- 3. Test www/non-www and http/https separately
Fixed route
- Specify header rules per path
- Simplifying forwarding
- Treat indexing and security headers separately