Public specification of a preferred URL for a page allows search engines to understand the original location for content.
The Open Graph protocol enables any web page to become a rich object in a social graph, a open protocol supported by Facebook
[url] uses conditional comments that are supported by Microsoft Internet Explorer. They allow web developers to show or hide HTML code based on the version of the viewer's browser.
Twitter cards make it possible for you to attach media experiences to Tweets that link to your content.
The DOCTYPE is a required preamble for HTML5 websites.
Defines the attributes of a web app in a simple JSON file. It describes how the web app should appear on the users system and how it should launch.
The @font-face rule allows for linking to fonts that are automatically activated when needed.
This page contains tags that are specific to an HTML 5 implementation.
The map tag is used to define a client-side image-map. An image-map is an image with clickable areas.
The page shows content with an iframe; an embedded frame that loads another webpage.
The defer attribute gives a hint to the browser that the script does not create any content so the browser can optionally defer interpreting the script. This can improve performance by delaying execution of scripts until after the body content is parsed and rendered.
A mechanism for developers to signal a relative priority for browsers to consider when fetching resources.
This page contains a meta robots tag which tells search engines and robots to index or not index the page.
The description attribute provides a concise explanation of the page content.
JSON-LD, or JavaScript Object Notation for Linked Data, is a method of transporting Linked Data using JSON.
JavaScript is a scripting language most often used for client-side web development.