add_header Strict-Transport-Security "max-age=63072000; includeSubDomains; preload" always;
add_header X-Content-Type-Options "nosniff" always;
add_header Referrer-Policy "no-referrer" always;
add_header Expect-CT "enforce, max-age=63072000" always;
add_header Cross-Origin-Opener-Policy "same-origin" always;
add_header Cross-Origin-Embedder-Policy "require-corp" always;
add_header Content-Security-Policy "default-src 'none'; connect-src 'self' https://releases.grapheneos.org/; font-src 'self'; img-src 'self'; manifest-src 'self'; script-src 'self'; style-src 'self'; form-action 'none'; frame-ancestors 'none'; block-all-mixed-content; base-uri 'none'; require-trusted-types-for 'script'" always;

# obsolete and replaced with Content-Security-Policy frame-ancestors 'none'
add_header X-Frame-Options "DENY" always;

# obsolete and replaced with strong Content-Security-Policy
add_header X-XSS-Protection "1; mode=block" always;