Some months ago, ISAW started adding Pleiades machine tags to the Ancient World Image Bank (AWIB) photos we've been uploading to Flickr. This post will explain what that means, how it might be useful to you and how you can add Pleiades machine tags to your own photos so we can find out about them.

Updated: 8:45pm EDT, 10 September 2011 (changes highlighted in orange).
Updated: 10:43am EST, 20 December 2011 (some of what's here is now superseded by recent developments; see further this new post: Pleiades, Flickr, and the Ancient World Image Bank)

Pleiades Machine Tags

Pleiades is a collaborative, open-access digital gazetteer for the ancient world. AWIB is an open-access publication that uses the Flickr photo-sharing site to publish free, reusable photos of ancient sites and artifacts. Machine tags are an extension to Flickr's basic tag-this-photo functionality that "use a special syntax to define extra information about a tag" (Aaron Straup Cope, "Ladies and Gentlemen: Machine Tags," 24 January 2007).

A Pleiades machine tag looks like this:

pleiades:place=795868

where 795868 is the stable identifier portion of a Pleiades Uniform Resource Identifier (URI). In this example, the URI corresponding to the machine tag above is:

http://pleiades.stoa.org/places/795868

Note what's in common between the machine tag and the URI (highlighted in yellow).

What Pleiades Machine Tags Are Good For

The Flickr API makes it possible to request lists of machine-tagged photos in the RSS webfeed format. So, to get a list of all photos in Flickr that are tagged with the example machine tag above, pop this into your feed reader:

http://api.flickr.com/services/feeds/photos_public.gne?tags=pleiades%3Aplace=795868&lang=en-us&format=rss_200

The same results can be viewed in HTML in a browser by resolving the following:

http://www.flickr.com/photos/tags/pleiades:place=795868

To get a list of all photos in Flickr that are tagged with any Pleiades machine tag, try this (the API syntax supports wildcards!):

http://api.flickr.com/services/feeds/photos_public.gne?tags=pleiades%3Aplace%3D&lang=en-us&format=rss_200

The same results, viewed in HTML on the Flickr site:

http://www.flickr.com/photos/tags/pleiades:place

Feeds like these aren't just for feed readers anymore. You can add user-interface widgets to your blog or website to summarize the latest content for your readers (check out the right-hand column in this blog). You can hook up services like Networked Blogs or Twitterfeed to pass on the latest changes to your Facebook friends or Twitter followers. If you've got a web-facing numismatic database that you've already linked up with Pleiades for the mint locations, you could write custom code to pull a corresponding picture of the ancient site into your web interface (say, alongside the map you've already got).

Add Pleiades Machine Tags to Your Own Photos on Flickr

Many of you have been taking amazing photos of ancient sites and artifacts for years. Many of you have posted some of them to Flickr and shared them with great groups like Chiron, Visibile Parlare - Greek Inscriptions and Visibile Parlare - Latin Inscriptions. If you'd like these photos to appear in queries and feeds (like those described above), right alongside the photos that we're publishing via AWIB, all you have to do is add the appropriate Pleiades machine tags in Flickr. Just look up your site on Pleiades, copy the numeric ID from the URI in your browser's location bar, append it to the string "pleiades:place=" and tag your Flickr photos with it. In this way, you can help us improve findability of good photos of ancient sites and the artifacts found there for everyone on the web. Who knows ... maybe enough people will join us in this effort that we can someday get the Flickr development team to give Pleiades machine tags some extra love.

Kudos to:

Aaron Straup Cope for his blog post "Wildcard Machine Tag URLs" (18 July 2008) that showed me how to construct the API queries necessary to get the RSS feeds described above. That, and the Flickr API documentation on feeds.
Nate Nagy, Managing Editor of AWIB, who applies the tags and keeps AWIB rolling.
Dan Pet, from the Portable Antiquities Scheme, and Ryan Baumann, from the Center for Visualization and Virtual Environments at the University of Kentucky, who put me onto machine tags in the first place and helped me get up to speed.