an introduction to rdfa by mark birbeck

rdfa originates in work done on xhtml 2, but can be used in mark-up today

we need to unlock the metadata already in web-pages, as well as encourage people to add more

rdfa provides a generic way to do this by building on features already in html

<meta name=&quot; author &quot;content=&quot; Mark Birbeck &quot; /> <link rel=&quot; license &quot; href=&quot; http://creativecommons.org/licenses/by/2.0/ &quot; />

<meta name=&quot; author &quot;content=&quot; Mark Birbeck &quot; /> <link rel=&quot; license &quot; href=&quot; http://creativecommons.org/licenses/by/2.0/ &quot; />

<img src=&quot; http://farm1.static.flickr.com/...jpg &quot; /> Zakim Bridge by Paul Keleher <a rel=&quot;license&quot; href=&quot;http://creativecommons.org/licenses/by/2.0/&quot;> ... </a>

<img src=&quot; http://farm1.static.flickr.com/...jpg &quot; />

Zakim Bridge by Paul Keleher

<a rel=&quot;license&quot; href=&quot;http://creativecommons.org/licenses/by/2.0/&quot;> ... </a>

<img src=&quot; http://farm1.static.flickr.com/...jpg &quot; /> Zakim Bridge by Paul Keleher <a about =&quot; http://farm1.static.flickr.com/...jpg &quot; rel=&quot;license&quot; href=&quot;http://creativecommons.org/licenses/by/2.0/&quot;> ... </a>

<img src=&quot; http://farm1.static.flickr.com/...jpg &quot; />

Zakim Bridge by Paul Keleher

<a about =&quot; http://farm1.static.flickr.com/...jpg &quot; rel=&quot;license&quot; href=&quot;http://creativecommons.org/licenses/by/2.0/&quot;> ... </a>

Boston Harbor by Paul Keleher <span about=&quot;http://farm1.static.flickr.com/...jpg&quot; > A picture of <span property=&quot;title&quot; > Boston Harbor </span> </span> <span about=&quot;http://farm1.static.flickr.com/...jpg&quot; > A picture of <span property=&quot;title&quot; > Boston Harbor </span> taken by <span property=&quot;creator&quot; > Paul </span>. </span>

Boston Harbor by Paul Keleher

<span about=&quot;http://farm1.static.flickr.com/...jpg&quot; > A picture of <span property=&quot;title&quot; > Boston Harbor </span> </span>

<span about=&quot;http://farm1.static.flickr.com/...jpg&quot; > A picture of <span property=&quot;title&quot; > Boston Harbor </span> taken by <span property=&quot;creator&quot; > Paul </span>. </span>

<span about=&quot;http://farm1.static.flickr.com/...jpg&quot; > A picture of <span property=&quot;title&quot; > Boston Harbor </span> taken by <span property=&quot;creator&quot; content=&quot;Paul Keleher&quot; > Paul </span>. </span> Boston Harbor by Paul Keleher

<span about=&quot;http://farm1.static.flickr.com/...jpg&quot; > A picture of <span property=&quot;title&quot; > Boston Harbor </span> taken by <span property=&quot;creator&quot; content=&quot;Paul Keleher&quot; > Paul </span>. </span>

Boston Harbor by Paul Keleher

Christmas Lights by Paul Keleher <span about=&quot;http://farm1.static.flickr.com/...jpg&quot; > A picture of <span property=&quot;title&quot; > Christmas Lights </span> taken on <span property=&quot;created&quot; > December 1st </span>. </span> <span about=&quot;http://farm1.static.flickr.com/...jpg&quot; > A picture of <span property=&quot;title&quot; > Christmas Lights </span> taken on <span property=&quot;created&quot; content=&quot;2007-12-01&quot; > December 1st </span>. </span>

Christmas Lights by Paul Keleher

<span about=&quot;http://farm1.static.flickr.com/...jpg&quot; > A picture of <span property=&quot;title&quot; > Christmas Lights </span> taken on <span property=&quot;created&quot; > December 1st </span>. </span>

<span about=&quot;http://farm1.static.flickr.com/...jpg&quot; > A picture of <span property=&quot;title&quot; > Christmas Lights </span> taken on <span property=&quot;created&quot; content=&quot;2007-12-01&quot; > December 1st </span>. </span>

Christmas Lights by Paul Keleher <span about=&quot;http://farm1.static.flickr.com/...jpg&quot; > A picture of <span property=&quot;title&quot; > Christmas Lights </span> taken on <span property=&quot;created&quot; content=&quot;2007-12-01&quot; datatype=&quot;xs:date&quot; > December 1st </span>. </span>

Christmas Lights by Paul Keleher

<span about=&quot;http://farm1.static.flickr.com/...jpg&quot; > A picture of <span property=&quot;title&quot; > Christmas Lights </span> taken on <span property=&quot;created&quot; content=&quot;2007-12-01&quot; datatype=&quot;xs:date&quot; > December 1st </span>. </span>

Spiral Staircase by Paul Keleher <span about=&quot;http://farm1.static.flickr.com/...jpg&quot; > <span property=&quot;title&quot; > Spiral Staircases </span> taken by <span property=&quot;creator&quot; > Paul Keleher </span>. <span property=&quot;geo:lat&quot; content=&quot;42.359188&quot; / > <span property=&quot;geo:long&quot; content=&quot;-71.058291&quot; /> </span>

Spiral Staircase by Paul Keleher

<span about=&quot;http://farm1.static.flickr.com/...jpg&quot; > <span property=&quot;title&quot; > Spiral Staircases </span> taken by <span property=&quot;creator&quot; > Paul Keleher </span>. <span property=&quot;geo:lat&quot; content=&quot;42.359188&quot; / > <span property=&quot;geo:long&quot; content=&quot;-71.058291&quot; /> </span>

Spiral Staircase by Paul Keleher <span about=&quot;http://farm1.static.flickr.com/...jpg&quot; > <span property=&quot; geo:lat &quot; content=&quot; 42.359188 &quot; / > <span property=&quot; geo:long &quot; content=&quot; -71.058291 &quot; /> </span>

Spiral Staircase by Paul Keleher

<span about=&quot;http://farm1.static.flickr.com/...jpg&quot; > <span property=&quot; geo:lat &quot; content=&quot; 42.359188 &quot; / > <span property=&quot; geo:long &quot; content=&quot; -71.058291 &quot; /> </span>

<span about=&quot;http://www.w3.org/People/Ivan/#me&quot; > <span property=&quot;foaf:name&quot; > Ivan Herman </span> knows Mark Birbeck and they are meeting today. </span>

<span about=&quot;http://www.w3.org/People/Ivan/#me&quot; > <span property=&quot;foaf:name&quot; > Ivan Herman </span> knows Mark Birbeck and they are meeting today. </span>

<span about=&quot;http://www.w3.org/People/Ivan/#me&quot; instanceof=&quot;foaf:Person&quot; > <span property=&quot;foaf:name&quot; > Ivan Herman </span> knows Mark Birbeck and they are meeting today. </span>

<span about=&quot;http://www.w3.org/People/Ivan/#me&quot; instanceof=&quot;foaf:Person&quot; > <span property=&quot;foaf:name&quot; > Ivan Herman </span> knows Mark Birbeck and they are meeting today. </span>

<div about=&quot;urn:ISBN:0091808189&quot; instanceof=&quot;bib:book&quot; > A book. </div> <div about=&quot;urn:ISBN:1596913614&quot; instanceof=&quot;bib:book&quot; > A book. </div>

<div about=&quot;urn:ISBN:0091808189&quot; instanceof=&quot;bib:book&quot; > A book. </div> <div about=&quot;urn:ISBN:1596913614&quot; instanceof=&quot;bib:book&quot; > A book. </div>

<span about=&quot;http://www.w3.org/People/Ivan/#me&quot; > <span property=&quot;foaf:name&quot; > Ivan Herman </span> knows <span rel=&quot;foaf:knows&quot; resource=&quot;http://inter...blo.com/profile.html#&quot; > Mark Birbeck </span> and they are meeting today. </span>

<span about=&quot;http://www.w3.org/People/Ivan/#me&quot; > <span property=&quot;foaf:name&quot; > Ivan Herman </span> knows <span rel=&quot;foaf:knows&quot; resource=&quot;http://inter...blo.com/profile.html#&quot; > Mark Birbeck </span> and they are meeting today. </span>

<div rel=&quot;foaf:holdsAccount&quot; > <span instanceof=&quot;foaf:OnlineAccount&quot; > <span rel=&quot;foaf:accountServiceHomepage&quot; resource=&quot;http://www.twitter.com/&quot; > Twitter Name: </span> <span property=&quot;foaf:accountName&quot; > markbirbeck </span> </span> </div>

<div rel=&quot;foaf:holdsAccount&quot; > <span instanceof=&quot;foaf:OnlineAccount&quot; > <span rel=&quot;foaf:accountServiceHomepage&quot; resource=&quot;http://www.twitter.com/&quot; > Twitter Name: </span> <span property=&quot;foaf:accountName&quot; > markbirbeck </span> </span> </div>

summary about: determines what we're talking about property and content: set text values datatype: sets the type of a text value instanceof : sets the type of something resource: same as href , but not clickable rel and rev: had before, but now work with src

about: determines what we're talking about

property and content: set text values

datatype: sets the type of a text value

instanceof : sets the type of something

resource: same as href , but not clickable

rel and rev: had before, but now work with src

rdfa is basically microformat’s big brother daniel e. renfer rdfa is microformats done right bob ducharme

more information rdfa.info: http://rdfa.info my blog: http://internet-apps.blogspot.com software: http://www.swcube.com in detail: http://www.swcube.com/rdfa

rdfa.info: http://rdfa.info

my blog: http://internet-apps.blogspot.com

software: http://www.swcube.com

in detail: http://www.swcube.com/rdfa