This is the namespace document for the XML schema used in the Protocol for Web Description resources (POWDER). It defines the structure for Description Resources where these are serialized in XML.
The root element of a POWDER document.
This type defines the structure of the powder element, which can have two alternative forms. The former consists of two required child elements, namely, the attribution element, which must occur exactly one time, and the dr element, which must occur at least one time. In its latter form, the powder element has as required child elements, exactly one instance of attribution and attribution.
This element is used to encapsulate information about the current POWDER document. It can occur only one time in a POWDER document, and only as a child of the powder element.
This type defines the structure of the attribution element, which consists of seven child elements, namely, maker, which must occur exactly one time, and issued, validfrom, validuntil, abouthosts, certifiedby, and authenticate, which can occur at most one time.
We should decide whether we allow or not further elements, and/or whether we are considering or not to define them. This must be stated here.
This element is used to denote the author of the current POWDER document. It can occur only one time in a POWDER document, and only as a child of the attribution element.
We should decide whether a DR may have multiple authors. If we wish to support this, two solutions are possible: allow multiple instances of the maker element, or assign to maker a space-separated list of IRIs.
This element is used to denote the issue date of the current POWDER document. It can occur only one time in a POWDER document, and only as a child of the attribution element.
I would like to point out that dcterms:issued is defined both as an RDF property and as an XML element (see Dublin Core dcterms XML schema). This is just to have a definitive statement about the fact that we define a new element (i.e., wdr:issued) and don't use dcterms:issued.
This element is used to denote the date from which a POWDER document is valid. It can occur only one time in a POWDER document, and only as a child of the attribution element.
This element is used to denote the date until which a POWDER document is valid. It can occur only one time in a POWDER document, and only as a child of the attribution element.
This element states that all the resources that are described within the current POWDER document are available from the given (set of) host(s). It can occur only one time in a POWDER document, and only as a child of the attribution element.
This element provides a pointer, expressed as an IRI, to a third-party certifying the current POWDER document. It can occur only one time in a POWDER document, and only as a child of the attribution element.
Is it possible that multiple third parties certify the same POWDER document? In such a case, should we use multiple instances of certifiedby, or a white-separated list of IRIs?
This element provides a pointer, expressed as an IRI, to the authentication service provided by the author of the current POWDER document. It can occur only one time in a POWDER document, and only as a child of the attribution element.
From the DR document is not explicitly said which element includes authenticate (attribution? dr?).
Also, is it possible to have multiple authentication services? In such a case, should we use multiple instances of authenticate, or a white-separated list of IRIs?
This element denotes an ordered list of DRs. It can occur exactly one time in a POWDER document, and only as a child of the powder element.
This type defines the structure of the ol element, which consists of a required child element, namely, the dr element, which must occur at least one time. In addition, the ol element has an optional xml:id attribute.
This element denotes a Description Resource (DR). It can occur one or more times in a POWDER document, and only as a child of the powder element.
This type defines the structure of the dr element, which consists of two required child elements, namely, the iriset element, which must occur at least one time, and one element, occuring exactly one time, which can be either the descriptorset or the tagset element. In addition, the dr element has an optional xml:id attribute.
This element denotes a set of IRIs of the resources in the DR scope, expressed by a set of IRI constraints. It must occur at least one time in a DR, and only as a child of the dr element.
This type defines the structure of the iriset element, which consists of a set of elements, expressing constraints on IRIs, plus an additional element, namely, includeredirection, which specifies whether HTTP redirection is allowed or not.
To do.
To do.
To do.
To do.
To do.
To do.
To do.
To do.
To do.
To do.
To do.
To do.
To do.
To do.
To do.
To do.
To do.
To do.
To do.
To do.
To do.
To do.
This element is used to state whether (and which types of) HTTP redirection is allowed. It can occur at most one time, and only a child of the iriset element.
Is this element in the right place? Whether HTTP redirection is allowed or not is not an IRI constraint, but an instruction on how an IRI set definition must be processed. Probably the most appropriate way of expressing it is as an attribute of iriset.
This type defines the structure of the includeredirection element. Such element has a single attribute, ref, which can have the following values: HttpTempRedirect, HttpPermRedirect, HttpAnyRedirect, and HttpNoneRedirect (default value).
HttpTempRedirect, HttpPermRedirect, HttpAnyRedirect, and HttpNoneRedirect are here defined as xsd:tokens. Should we define them differently?
This element denotes the description of the resources in the DR scope, expressed by a set of descriptors, defined in specific vocabularies. It must occur exactly one time in a DR, and only as a child of the dr element.
This type defines the structure of the descriptorset element, which can have three alternative forms. The first consists of a required child unnamed element, corresponding to a descriptor defined in a specific vocabulary, which must occur at least one time. In addition, four optional child elements are supported, namely, displaytext, displayicon, sha1sum, and certified, which can all occur at most one time. In its second form, the descriptorset has all the above child elements, except the one corresponding to descriptors, but the displaytext element is mandatory. Finally, the third form consists of a required attribute ref, having as value the IRI of an existing instance of another descriptorset element, and no child elements.
Is this the correct definition? Also, attribute ref might refer to multiple descriptorsets?
This element is used to provide a textual summary of the statements in a DR. It can occur only one time in a DR, and only as a child of the descriptorset element.
Shouldn't we support this element also for tagset?
This element is used to provide the IRI of an image corresponding to the graphic summary of a DR. It can occur only one time in a DR, and only as a child of the descriptorset element.
This element is used to encapsulate the SHA1 sum of a DR. It can occur only one time in a DR, and only as a child of the dr element.
Is this the right place for this element? Shouldn't the SHA1 sum concern the whole POWDER document, instead of a single DR?
This element is used to state whether a DR has been certified by a third-party or not.. It can occur only one time in a DR, and only as a child of the dr element.
Is this the right place for this element? Shouldn't it apply to the whole POWDER document, instead of a single DR?
Also, in the DR document, Section 5.2, it is said that certifiedby is the inverse of certified. This is not correct: certifiedby states who certifies the current POWDER doc, whereas certified just states whether a DR is certified or not. Since certified can be expressed as a triple DR certified true (or false), the inverse does not make sense to me.
My suggestion is to remove element certified, and use just certifiedby.
This element denotes the description of the resources in the DR scope, expressed by a set of free text tags. It must occur exactly one time in a DR, and only as a child of the dr element.
This type defines the structure of the tagset element, corresponding to one or more instances of the tag element.
This element denotes a free text tag, describing a characteristics of the resources in the DR scope. It must occur at least one time in a DR, and only as a child of the tagset element.