Website using the £ symbol on their website - meaning it may accept payment in this British currency.
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.
AddThis, the new brand name for Clearspring Technologies, is the leader in socially connecting publishers, services and advertisers to audiences on the open web. Reaching more than 1.3 billion unique users monthly, AddThis’ social tools and analytics are used on more than 14 million unique domains to distribute and track digital...
Open graph description entity tag
Any offered product or service. For example: a pair of shoes; a concert ticket; the rental of a car; a haircut; or an episode of a TV show streamed online.
Sites who has this tag are verfied by google to use WebMaster tools