Websites that have a shopping cart or checkout page, either using a known ecommerce platform or a custom solution.
Envoy is an open-source edge and service proxy, designed for cloud-native applications.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Open Graph is a protocol that is used to integrate any web page into the social graph.
Varnish is a reverse caching proxy.