The W3C POWDER Working Group has posted second last call working drafts of three specs:
According to the formal semantics,
The Protocol for Web Description Resources, POWDER, offers a simple method of associating RDF data with groups of resources. Its primary 'unit of information' is the Description Resource (DR). This comprises three elements:
- attribution (who is providing the description)
- scope (defined as a set of IRIs over which the description applies to the resources de-referenced from those IRIs)
- the description itself (the 'descriptor set').
To some extent, this approach is in tension with the core semantics of RDF and OWL. To resolve that tension, it is necessary to extend RDF semantics as described below. In order to minimize the required extension, while at the same time preserving the relatively simple encoding of POWDER in XML which is generally readable by humans, we define a multi-layered approach. The operational semantics, i.e. the encoding of POWDER in XML, is first transformed into a more restricted XML encoding that is less easily understood by humans and depends on matching IRIs against regular expressions to determine whether or not they are within the scope of the DR. This latter encoding is, in its own turn, transformed into the extended-RDF encoding.
