- Redirect chain
- The sequence of HTTP responses that forwards one URL to another.
- CORS
- Browser-enforced rules controlling whether one web origin may read responses from another.
- Preflight
- An OPTIONS request a browser may send to check CORS permission before the real request.
- SPF
- A DNS policy listing servers authorized to send mail for a domain.
- DMARC
- An email-authentication policy telling receivers how to handle SPF or DKIM failures.
- Canonical URL
- A page’s declared preferred URL for indexing duplicate or similar content.
- Open Graph
- Page metadata used by social platforms to build link previews.
- SSRF protection
- Server-side checks that block requests to private or sensitive network destinations.