PUBLIC MARKS from Spone with tag semantic

rel="logo" is a proposed standard for serving and maintaining up-to-date logos for use in various media. By including a line of code on your site that links to a scalable vector logo, you make it very easy for other websites, applications, readers, clients, and stations to ensure that they are using an approved logo directly from you.

Common Tag is an open tagging format developed to make content more connected, discoverable and engaging. Unlike free-text tags, Common Tags are references to unique, well-defined concepts, complete with metadata and their own URLs. With Common Tag, site owners can more easily create topic hubs, cross-promote their content, and enrich their pages with free data, images and widgets.

Faviki is a social bookmarking tool that lets you tag bookmarks using Wikipedia concepts as tags. Faviki lets you keep your own tags and connect them to common, universal concepts from the world's largest collection of knowledge!

DBpedia is a community effort to extract structured information from Wikipedia and to make this information available on the Web. DBpedia allows you to make sophisticated queries against Wikipedia, and to link other data sets on the Web to Wikipedia data.