Meta Tags: The Poor Man’s RDF? I’ve always thought that what makes del.icio.us so successful despite a lot of recent competition is that it exemplifies the same kind of thinking Tim Berners-Lee described in his “ Axioms of Web Architecture ” as the “Principle of Least Power,” or what the designers of the Internet called “end-to-end architecture.” Instead of trying to build a powerful, heavyweight system that would anticipate a user’s every need, Joshua and company have been building an extremely simple, general service that can be endlessly adapted and easily plugged into other systems. The variety of “meta” tagging schemes del.icio.us users have evolved is great evidence of this. Probably the best known example, the “for:” tag prefix, has actually become commonly enough used that Joshua and company have given it formal recognition within the system, but there are lots of other schemes in usage.
It was this last usage that led me to an epiphany. Machine tags. Straup says: [Note : I work here and this message was also sent to the API mailing list] We are rolling out a new feature called "machine tags" that allows users to be more precise in how they tag, and how they search, their photos. Many of you may already be familiar with machine tags by another name (triple tags) or because you are already using them, informally, in your code (for example, "geo:long=123.456"). "Machine tags" is the technical term for the extra hamsters we've added to the Flickr servers to formalize how these sorts of tags are treated. I've included a "Ceci n'est pas un FAQ" below with all the details. For the moment, machine tags are principally an API "thing". Enjoy! # What are machine tags? Machine tags are tags that use a special syntax to define extra information about a tag.
Machine tags have a namespace, a predicate and a value. Like tags, there are no rules for machine tags beyond the syntax to specify the parts of a machine tag. . * flickr:user=straup * medium:paint=oil. AbstractTagging - Django Projects - Trac.