concept link in category data

This is an excerpt from Manning's book Linked Data: Structured data on the Web. Login to get full access to this book.

*	Data is available on the Web, in whatever format (for example, a scanned image).
**	Data is available as machine-readable structured data (for example, an Excel spreadsheet).
***	Data is available in a non-proprietary format (for example, CSV).
****	Data is published using open data standards from the World Wide Web Consortium.
*****	All of the above apply, plus links to other people’s data.

Figure 1.5. The Linked Open Data cloud in late 2011. The circles represent freely available datasets and the arrows represent links between them.

An example of this principle at work can be seen in listing 1.1. That listing includes links to the DBpedia description of Galway Airport and the unit of measure for days.

<link rel="alternate" type="text/turtle" href="http://
     yourPublicWebSpace/FOAF.ttl" title="My FOAF" />
Include references to the FOAF files of your friends by including links to those files in your FOAF profile. For example, you can reference Marsha’s FOAF description by adding rdfs:seeAlso <http://rosemary.umw.edu/~marsha/foaf.ttl>
You could also use seeAlso to provide a link to a Facebook, LinkedIn, or Pinterest account of yourself or a friend.