Websites using some form of Captcha technology on them.
See what your Facebook friends have liked, shared, or commented on across the Web. This includes all variations of Like, Share and Follow Buttons, Embedded Posts, Comments, Activity Feed, Recommendations Feed, Recommendations Bar, Like Box and Facepile.
Let visitors recommend your content on Google Search and share it on Google+.
Google+ platform websites integration using the Google+ platform tag.
This site uses the viewport meta tag which means the content may be optimized for mobile content.
nginx [engine x] is a HTTP server and mail proxy server written by Igor Sysoev.
A family of standard web feed formats used to publish frequently updated information like blog entries, news headlines, audio and video.
A pingback is one of four types of linkback methods for Web authors to request notification when somebody links to one of their documents. This enables authors to keep track of who is linking to, or referring to their articles.
Website using the £ symbol on their website - meaning it may accept payment in this British currency.
UTF-8 (8-bit UCS/Unicode Transformation Format) is a variable-length character encoding for Unicode. It is the preferred encoding for web pages.
A canonical link element is an HTML element that helps webmasters prevent duplicate content issues by specifying the "canonical", or "preferred".
This page contains a meta robots tag which tells search engines and robots to index or not index the page.