Alice has a set of files on her desktop computer, some of which she would like to directly publish on the Internet. Each of these files has at least one URI–its local file URI. Alice would like to annotate each of these URIs with an additional URI reference indicating its web-accessible URL. She would like to do this without specifying a full URI for each annotation, but would instead like to organize them hierarchically as her files are organized. When Alice adds a new name to her list of published items, she would like to provide the name in as simple a manner as possible, so that full URIs for both the file and its publishing location are based upon the context of her chosen organizational scheme.

The root element of a WebCap document is the cap:capabilities element. First, it contains a cap:relationship element that describes the intended RDF relationship that exists between entries in a mapped bundle. Next, it contains an optional cap:description element that allows a user to enter a colloquial description of the nature of the mapping contained in the current document. Finally, the root element contains a sequence of one or more cap:map elements that provide the mapped URI bundles.

The cap:relationship allows the user to define an RDF property between resources identified within mapped bundles in the current WebCap document. This element SHOULD contain a single child element; the RDF URI reference for the property to use is determined from the QName of this element as described in section 2.1 of the RDF/XML Syntax Specification. If A and B are any two members of a mapped bundle in the current document, this RDF property is considered to hold between those two members if B comes after A in document order. For this reason, the RDF property defined within the cap:relationship element SHOULD be a transitive property.

This single property is intended to describe how the members of mapped bundles within the current document are related, which should be homogenous within a given WebCap document. In order to make additional statements about these resources and their relationships, users should use distinct WebCap documents or more powerful applications, such as RDF.

The cap:description element may have arbitrary content; its purpose is to provide a location for a human-readable description of the purpose of the current WebCap document. We suggest using either plain text or XHTML content within this description.

The cap:map defines a single URI mapping bundle within a WebCap capability list and potentially provides a basis for other bundles. This element may contain either a cap:all element or a selection of no more than one each of cap:local, cap:global, and cap:exposed elements, which designate the members of the current mapping bundle. This element may also contain any number of additional cap:map elements; these define additional mapping bundles and do not contribute to the current mapping bundle.

Applications SHOULD ignore other children of the cap:map element in the ahttp://infinitesque.net/2006/ns/capabilities/ namespace, and SHOULD treat children of the cap:map in other namespaces as additional entries in the current mapping bundle. Other specifications SHOULD define the intended meaning of the URIs in such entries.

These elements directly designate one URI component of the mapping bundle for the parent cap:map. Each of these elements MUST be a child of a cap:map element, and the contents of each of these elements MUST be a shorthand reference (which is syntactically the same as a relative reference). To determine the effective URI for this component, follow these steps:

A cap:local URI SHOULD be considered to be a locally available identifier for a resource without an expectation of global uniqueness (such as a URI using the file scheme). A cap:global URI SHOULD be considered to be a globally unique identifier for a resource without an expectation of any retrieval semantics. A cap:exposed URI SHOULD be considered to be the globally unique identifier for a resource that is or will be available for the defining capability offered by the current WebCap document.

The cap:all element is shorthand for designating several URI components at once. This element MUST be the child of a cap:map element, its current map, and the current map MUST be the child of another cap:map element, the parent map. The contents of this element MUST be a shorthand reference. A cap:all element is equivalent to a sequence of the same cap:local, cap:global, and cap:exposed elements that are children of the parent map, with their contents all equal to the contents of this element.