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Darwin Core Namespace Policy
| Title: | Darwin Core Namespace Policy |
|---|---|
| Date Issued: | 2009-02-12 |
| Abstract: | All terms in the Darwin Core must be assigned a unique URI. For convenience, the term URIs that are assigned and managed by the Darwin Core Task Group are grouped into collections known as Darwin Core namespaces. This document describes how term URIs are allocated by the Darwin Core Task Group and the policies associated with Darwin Core namespaces. |
| Contributors: | John Wieczorek (MVZ) |
| Legal: | This document is governed by the standard legal, copyright, licensing provisions and disclaimers issued by the Taxonomic Databases Working Group. |
| Part of TDWG Standard: | ***URL to DwC Standard*** goes here |
| Creator: | Darwin Core Task Group |
| Identifier: | http://rs.tdwg.org/dwc/terms/namespace/2009-02-12/ |
| Latest Version: | http://rs.tdwg.org/dwc/terms/namespace/ |
| Replaces: | Not applicable |
| Replaced By: | Not applicable |
| Translations: | http://rs.tdwg.org/dwc/translations/ |
| Document Status: | This is a TDWG Request for Comment. |
Table of Contents
| 1. Glossary |
| 2. Introduction |
| 3. References |
| 4. Darwin Core Namespace URIs |
| 5. Policy concerning classes of changes to Darwin Core terms |
| 6. Persistence Policy |
1. Glossary
This document uses the following terminology:
- term
- A property (element), class, vocabulary encoding scheme, or syntax encoding scheme.
- URI
- A Uniform Resource Identifier (URI) or Internationalized Resource Identifier (IRI).
- Darwin Core term
- A term that is declared and maintained by Darwin Core Task Group.
- term URI
- The URI that identifies a term.
- Darwin Core term URI
- The URI for a term that is declared and managed by Darwin Core Task Group.
- term name
- A unique token assigned to a term. For all Darwin Core terms, the term name is appended to a Darwin Core namespace URI to create the Darwin Core term URI.
- term label
- A human-readable label assigned to a term.
- Darwin Core namespace
- A collection of Darwin Core term URIs where each term is assigned a URI that starts with the same 'base URI'. The 'base URI' is known as the Darwin Core namespace URI. (Note that a Darwin Core namespace is not the same as an 'XML namespace').
- Darwin Core namespace URI
- The URI that identifies a Darwin Core namespace.
- Darwin Core recommendation
- A specification, approved through Darwin Core's formal process, which may define one or more Darwin Core terms.
- Darwin Core term declaration
- A representation of one or more Darwin Core terms.
Term URIs are grouped into Darwin Core namespaces in order to ease the assignment of URIs to terms and to streamline their use in particular encoding syntaxes. Note that the grouping of term URIs into Darwin Core namespaces is orthogonal to the grouping of terms into sets designed to meet other functional needs, e.g., as various types of vocabularies.
2. Introduction
This document and the policies contained herein are modeled on the Dublin Core Metadata Initiative Namespace Policy [DCMINAMESPACEPOLICY]. All terms in the Darwin Core must be assigned a unique URI. For convenience, the term URIs that are assigned and managed by the Darwin Core Task Group are grouped into collections known as Darwin Core namespaces. This document describes how term URIs are allocated by the Darwin Core Task Group and the policies associated with Darwin Core namespaces.3. References
| [DCMINAMESPACEPOLICY] | http://dublincore.org/documents/2007/07/02/dcmi-namespace/ | DCMI Namespace Policy, 2 July 2007 |
| [DWC] | http://rs.tdwg.org/dwc/ | An introduction to the Darwin Core Standard. |
| [DWC-MAIL] | tdwg-content@lists.tdwg.org | Mailing list for commentary and discussion on Darwin Core. |
| [DWC-USAGE] | tdwg-tag@lists.tdwg.org | TDWG Architecture Mailing List. |
| [DWC-TYPE] | http://rs.tdwg.org/dwc/terms/type-vocabulary/ | Darwin Core Type Vocabulary. |
| [DECISIONS] | http://rs.tdwg.org/dwc/terms/history/decisions/ | A history of decisions resulting in changes to Darwin Core terms. |
| [HISTORY] | http://rs.tdwg.org/dwc/terms/history/ | Darwin Core Terms: A complete history. |
4. Darwin Core Namespace URIs
The Darwin Core namespace URI for the collection of all Darwin Core properties, classes and encoding schemes is:
http://rs.tdwg.org/dwc/terms/
The Darwin Core namespace URI for the collection of classes in the Darwin Core Type Vocabulary [DWC-TYPE] is:
http://rs.tdwg.org/dwc/dwctype/
All future Darwin Core namespace URIs (additional Darwin Core controlled vocabularies for example) will conform to this pattern:
http://rs.tdwg.org/dwc/namespace_label/
All Darwin Core namespace URIs will dereference to a Darwin Core term declaration for all the terms with term URIs within that Darwin Core namespace. A machine-processable Darwin Core term declaration will be made available.
Some example Darwin Core term URIs follow:
http://rs.tdwg.org/dwc/terms/ScientificName
is the Darwin Core term URI for the ScientificName property.
http://rs.tdwg.org/dwc/dwctype/PreservedSpecimen
is the Darwin Core term URI for the PreservedSpecimen class in the Darwin Core Type Vocabulary.
Each Darwin Core term can be so identified.
All Darwin Core term URIs will dereference to a Darwin Core term declaration for the identified term. A machine-processable Darwin Core term declaration will be made available.
5. Policy concerning classes of changes to Darwin Core terms
Changes to Darwin Core terms or term declarations will occur from time to time for a variety of reasons. Such changes have varying implications for Darwin Core term URIs and Darwin Core namespaces. The following classes of changes are identified along with examples and associated implications.
In all cases, any changes to Darwin Core terms or term declarations will result in an update to the versioning information carried in the Darwin Core recommendation and/or Darwin Core term declaration associated with that term. Specifically, a new version of the term will be created with appropriate information in the Version, Replaces, and DateModified attributes of the new term, and with the identifying version information of the new term in the Is Replaced By attribute of the term being updated.
5.1. Minor editorial errata
Errors of spelling, punctuation, or other clerical mistakes discovered in Darwin Core recommendations and/or Darwin Core term declarations will be corrected without a comment period, following notification to the TDWG Architecture Group [DWC-USAGE], as long as, in the judgment of the TDWG Architecture Group, there are no implications for negative impact on users or applications that rely on those Darwin Core term declarations. Minor editorial changes of this type will result in no changes to Darwin Core term URIs, will not undergo a request for comments, and will not result in a decision [DECISIONS].
5.2. Substantive editorial errata
Errors of substance discovered in Darwin Core recommendations and/or Darwin Core term declarations will trigger public notification of the correction to the Darwin Core mailing list [DWC-MAIL]. Errors that, in the judgment of the TDWG Architecture Group, compromise the immediate usefulness or accuracy of systems based on Darwin Core will be corrected immediately (for example, an incorrect URL to a resource external to Darwin Core). Others will be corrected following a 30-day public comment period to assure that changes do not adversely effect systems or applications which rely on the Darwin Core namespace infrastructure. Substantive editorial changes of this type will result in no changes to Darwin Core term URIs, and will not result in a decision [DECISIONS].
5.3. Semantic changes in Darwin Core terms
Changes of definitions within Darwin Core recommendations and/or Darwin Core term declarations will be reflected in the affected Darwin Core recommendation and/or Darwin Core term declaration. Semantic changes of this type will, will undergo a request for comments, and will result in a decision [DECISIONS]. If, in the judgment of the TDWG Architecture Group, such changes of meaning are likely to have substantial impact on either machine processing of Darwin Core terms or the functional semantics of the terms, then these changes will be reflected in a change of URI for the Darwin Core term or terms in question. The URIs for any new Darwin Core namespaces resulting from such changes will conform to the Darwin Core namespace URI pattern defined above.
Requests for semantic changes to a term should be made to the Technical Architecture Group [DWC-USAGE], and should consist of a complete list of attributes to be changed along with a statement of justification for the changes.
5.4. Addition of Darwin Core term declarations to existing Darwin Core namespaces
New Darwin Core term URIs will occasionally be added to existing Darwin Core namespaces based on public demand. Addition of Darwin Core term URIs to existing Darwin Core namespaces will not trigger changes in Darwin Core namespace URIs. Additional term requests that are determined by the Technical Architecture Group to have merit will undergo a request for comments and will not result in a decision [DECISIONS].
Requests for additional terms should be made to the Technical Architecture Group [DWC-USAGE], and should consist of a complete list of attributes as given in the introduction in the Darwin Core Terms history [HISTORY] along with a statement of justification for the new term, including an explanation of why no existing term will suffice.
6. Persistence Policy
TDWG recognizes that people and applications depend on the persistence of formal documents and machine processable schemas that have been made publicly available. In particular, the stability of Darwin Core term URIs and Darwin Core namespace URIs is critical to interoperability over time. Thus, the wide promulgation of this set of URIs dictates that they be maintained to support legacy applications that have adopted them.
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