Principals

All,

More for reference purposes, since it isn't going into the WebID spec.

WebDAV Access Control Ext. Spec [1]:

       A "principal" is a distinct human or computational actor that
       initiates access to network resources.  In this protocol, a
       principal is an HTTP resource that represents such an actor.

Translation:

A data object that represents a human or computational actor (e.g. 
software agent). This representation is achieved as follows:

1. data object ID is a resource URL
2. data object representation is an entity relationship model based 
description graph
3. the graph is comprised of attribute=value pairs that coalesce around 
the ID (a de-referencable URI) that denotes the entity represented by 
said data object.

Example:

1. http://kingsley.idehen.net/dataspace/person/kidehen -- denotes a data 
object resource
2. http://kingsley.idehen.net/dataspace/person/kidehen#this -- denotes 
the real world entity that is the focal point (via attribute=value pair 
coalescence) for the description graph.

Linked Data use the magic of de-reference to make this very cool and 
neat since the URI denoting the real world entity resolves to a data 
object resource that represents a description of the  real world 
entity's description.

Links:

1.  http://tools.ietf.org/html/rfc3744 -- WebDAV ACL extensions rfc
2. http://youtu.be/f-pJlnpkLp0 -- a favorite fun video about pointers 
and dereference .

-- 

Regards,

Kingsley Idehen	
Founder & CEO
OpenLink Software
Company Web: http://www.openlinksw.com
Personal Weblog: http://www.openlinksw.com/blog/~kidehen
Twitter/Identi.ca handle: @kidehen
Google+ Profile: https://plus.google.com/112399767740508618350/about
LinkedIn Profile: http://www.linkedin.com/in/kidehen