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.
A family of standard web feed formats used to publish frequently updated information like blog entries, news headlines, audio and video.
The http-equiv attribute provides an HTTP header for the information/value of the content attribute. The http-equiv attribute can be used to simulate an HTTP response header.
A canonical link element is an HTML element that helps webmasters prevent duplicate content issues by specifying the "canonical", or "preferred".