Website using the ¥ symbol on their website - meaning it may accept payment in this South Korean currency.
Google+ platform websites integration using the Google+ platform tag.
The Tweet Button is a small widget which allows visitors to share content and connect on Twitter.
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.
This page contains a meta robots tag which tells search engines and robots to index or not index the page.
A canonical link element is an HTML element that helps webmasters prevent duplicate content issues by specifying the "canonical", or "preferred".