Flickr Machine Tags

Flickr recently announced a new feature called "machine tags". From their announcement:

"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.

Machine tags follow a lightweight format:

namespace:predice=value

The namespace defines a class or a facet that a tag belongs to ('geo', 'flickr', etc.) The predicate is name of the property for a namespace ('latitude', 'user', etc.) The value is, well, the value.

Like tags, there are no rules for machine tags beyond the syntax to specify the parts of a machine tag

Tags that follow this format are automatically grouped under "machine tags" in the Flickr user interface, and can be hidden or shown by the user.

Machine tags, while not having a name, have been around for a while, their usage driven by people's urge to organize tags and give them specific semantics - and then, to build applications on top of this, assuming this specific semantics. I've discussed this a while ago, when I was younger. Back then, I suggested the name "applitags" for this feature, and suggested a slightly different format for differentiating Machine Tags (or applitags) from People Tags:

x:namespace.tag[=value]

I do wish the Flickr folks would have gone a step further and formalized the namespacing issue as well, as this would have made software built on top of Machine Tags more reliable. Still, this is an important move, coming from one of the tags-trend-setting players.

Are we re-building XML from the ground up all over again though?

Technorati Tags: flickr Machine+Tags applitags XML tagging