AC Scratch

Work in progress: Please do not edit this page while you see this. Expecting to finish by about — BobMorris Last edit of page on: 2011-08-16 This is a sandbox for testing AC formats. Please don't mess with it without talking to BobMorris 04:17, 28 July 2011 (CEST)

Title: Audubon Core

Date: TBD. This document is a proposal

Abstract: The Audubon Core is a set of vocabularies designed to represent metadata for biodiversity multimedia resources and collections. These vocabularies aim to represent information that will help to determine whether a particular resource or collection will be fit for some particular biodiversity science application before acquiring the media. Among others, the vocabularies address such concerns as the management of the media and collections, descriptions of their content, their taxonomic, geographic, and temporal coverage, and the appropriate ways to retrieve, attribute and reproduce them.

Contributors: Robert A. Morris, Vijay Barve, Mihail Carausu, Vishwas Chavan, Jose Cuarda, Chris Freeland, Gregor Hagedorn, Patrick Leary, Dimitry Mozzherin, Annette Olson, Greg Riccardi, Ivan Teage

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: TBD

This document has version 1.0.1 and MRTG Wiki revision ID 19029 with a permalink http://www.keytonature.eu/w/index.php?title=Audubon_Core&oldid=19029

The version presently under internal review is http://www.keytonature.eu/w/index.php?title=Audubon_Core&oldid=18780

This is the normative documentation for the TDWG Audubon Core Multimedia Resources Metadata Standard (Audubon Core, or simply AC), During development, it was colloquially known as MRTG, after its developers, the GBIF-TDWG Joint Multimedia Resources Metadata Task Group. Please see the brief non-normative document linked at Audubon Core Non normative document and also MRTG Development History for the development history in detail.

If you are unfamiliar with the AudubonCore, please read the Audubon Core Non normative document before editing this page. It lays out why there is perceived a need for a biodiversity media resource metadata schema, and how the standard attempts to use existing metadata standards where possible.

1 Related Information

→ Information about submission as TDWG standard
→ MRTG Wiki Homepage
→ Current Schema Draft. This version is under internal review as part of the submission to TDWG.
→ Audubon Core Non normative document
→ MRTG Development History
→ MRTG Meeting Notes
→ MRTG Best Practices
→ XML Schema representation of Audubon Core
→ RDF representation of Audubon Core
→ MediaWiki Help

• Go here for Discussion of theXML Schema For MRTG. This is obsolete and will be revised for compliance with the normative version when it is approved.
• Go here for Discussion of the MRTG in RDF. This is obsolete and will be revised for compliance with the normative version when it is approved.
• TDWG09 MRTG WORKGROUP REPORT

2 Terminology of this specification

There are many ways to organize metadata specifications, particularly as to the nomenclature of the constituents of the metadata. In this document and the associated non-normative documentation, we will follow closely (sometimes verbatim) a portion of the Dublin Core Metadata Initiative (DCMI) metadata nomenclature as described in Section 2.3 of the DCMI Abstract Model (http://www.dublincore.org/documents/abstract-model/). In addition:

• A Multimedia Resource is anything that a provider identifies as belonging to one of the possible values of the AC Type term and one of the Subtype term values. A mechanism is provided by which providers can supply a privately defined subtype that will not collide with the AC defined Subtype values.
• An AC record is a set of terms with any values conforming to this document, and which contain at least the six mandatory terms described below, and which describes a single multimedia resource (possibly including a Collection). One of these, the value of Identifier is a Globally Unique IDentifier (GUID), which may have been assigned to the resource by an external authority or by the provider of the metadata record.
• AC terms are divided into two Layers. Those characterized as in the Core Layer, including the six mandatory terms, should be meaningfully handled by all consuming clients applications. Only wholly complete consuming applications need handle those in the Extended Layer'.

In this document, every AC term has a Name, a URI, a plain text normative Definition, a recommended English Label, an optional "Details" attribute, and an optional "Comments" attribute. In addition, a term has an attribute telling whether it is mandatory, one telling whether it is repeatable, and one telling whether it is in the "Core" or "Extended" Layer. The Extended Layer comprises terms likely to only occur for certain media. For example, the term DateAvailable will apply only to media that are embargoed, but for which the provider is prepared to make the metadata immediately available.

It is strongly recommended that consuming applications be able to meaningfully handle all Core terms, and that only wholly complete consuming applications need handle Extended Layer terms. What is meant by "meaningfully handle" is up to implementers of this normative specification. It could be as simple as "gracefully ignore".

AC metadata can describe either individual multimedia resources or collections of resources. A few, but not many, of the AC properties have different values for collections than for individual media. If no such distinction is mentioned, AC does not assume one.

Term Names for terms borrowed from other vocabularies are those in use for the corresponding term in those vocabularies. Term names are intended principally for navigation in this document. Term Labels are suggestions for English labels in applicationa. They are recommendations only and are offered only in English, with the added expectation that they may clarify intended usage of the term. Communities may wish to promulgate recommendations for Labels in other languages, or even alternative English Labels for specialized audiences, e.g. school children.

URI's for terms conform to the http URI scheme (See, http://en.wikipedia.org/wiki/URI_scheme, http://www.w3.org/TR/uri-clarification/, or http://www.ietf.org/rfc/rfc2396.txt ). Informally, one may understand this as follows: an http URI has the syntax of an http URL, but there is no expectation that putting it in a web browser will result in any information being returned to the browser, and if there is, it may have no relevance. This conformance requirement applies only to the URIs that identify AC terms. A few AC terms permit values to be taken from another controlled vocabulary chosen by the user. In this case, those values may involve URIs conforming to a scheme given by that external vocabulary, and AC is silent on what that scheme is.

The Details field of a term's documentation points to further information, if any exists, about the term. In particular, for terms borrowed from other vocabularies, this field generally carries a link to the originating vocabulary's documentation for that term.

3 Media Collections

AC metadata can describe either individual multimedia resources or collections of resources. A few, but not many, of the AC terms have different values for collections than for individual media. If no such distinction is mentioned, AC does not assume one.

4 Multiplicity

A number of terms do not permit repetition within a single AC metadata record, sometimes in cases where there seems a compelling case for more than one value for a term. A typical example is the term #Reviewer, being the name of an individual providing some natural language expert review of a resource, typically given as the value of the term #Review_Comments. Clearly, more than one person might provide such a review, but in this case something has to specify which reviewer made which comments. There are several solutions to this kind of problem, which is endemic to many kinds of descriptive metadata. One is to have some kind of linkage between the related terms. This alone is not sufficient, as we see from this example: a reviewer might make several comments, several reviewers might together make several comments, and some other group of reviewers might make some other group of comments, etc. This the linkage approach requires not only linkages between many terms, but also container objects holding multiples, and linkages between those containers and other objects. Other even more complex ways to allow aggregation of terms to provide relations between them are possible. MRTG has chosen instead to have entirely flat terminology (with the sole exception of the #Access_Point_Class) but this does not preclude multiple values. At the small cost of having to repeat some of the term values (including the 7 required ones), a description can contain several metadata records for the same Multimedia Resource. Consider for example the following pseudo-code in an imaginary spreadsheet implementation of AC. In this example, the implementing language requires an additional spreadsheet term named EOR ("End of Record") separating several metadata records for the same image (because they have the same Identifier) from one another.

Term	Value
Identifier	http://bit.ly/pwrmwD
Type	image
… (many terms)	…
Reviewer	Susan Grogan
Comments	Excellent Image
EOR	Yes
Identifier	http://bit.ly/pwrmwD
Type	image
… (required terms only)	…
Reviewer	Jonathan Smythe
Reviewer Comments	Colors are inaccurate
EOR	Yes

5 Vocabulary Index

5.1 By Name

#Identifier #Type

6 Management Vocabulary

Term: dcterms:identifier
Normative URI:	http://purl.org/dc/terms/identifier
Label	Identifier
	Layer: Core — Required: ‘Yes’ for media collections, ‘No’ for media resources (but preferred if available) — Repeatable: Yes
Definition:	An arbitrary code that is unique for the resource, with the resource being either a provider, collection, or media item.
Details	dcterms:identifier
Comments:	Recommend to follow dwc best practices. Using multiple identifiers implies that they have a same-as relationship, i.e. they all identify the same object (e. g. an object may have an http-URL, and lsid-URI, and a GUID-number).
Crosswalk:	DublinCore: dcterms:identifier — XMP: — DarwinCore: — NCD: ncd:collectionId — Morphbank: URL with id — LIFE: System ID — K2N: k2n:Resource_ID — MIX2.0: mix2:BasicDigitalObjectInformation/ObjectIdentifier
Term: dcterms:type
Normative URI:	http://purl.org/dc/terms/type
Label	Type
	Layer: Core — Required: Yes — Repeatable: No
Definition:	Any dcmi type term from http://dublincore.org/documents/dcmi-type-vocabulary/ may be used. Recommended terms are Collection, StillImage, Sound, MovingImage, InteractiveResource, Text. Also recommended are PanAndZoomImage , 3DStillImage, and 3DMovingImage.
Details	dcterms:type
Comments:	A Collection should be given type http://purl.org/dc/dcmitype/Collection. If the resource is a Collection, this item does not identify what types of objects it may contain. Following the DC recommendations at http://purl.org/dc/dcmitype/Text, images of text should be marked as Text.
Crosswalk:	DublinCore: dcterms:type — XMP: — DarwinCore: — NCD: ncd:CollectionType — Morphbank: — LIFE: Type — K2N: k2n:Type pro parte — MIX2.0:
Term: subtype
Normative URI:	http://rs.tdwg.org/ac/terms/subtype
Label	Subtype
	Layer: Core — Required: No — Repeatable: Yes
Definition:	Any of Drawing, Painting, Logo, Icon, Illustration, Graphic, Photograph, Animation, Film, SlideShow, DesignPlan, Diagram, Map, MusicalNotation, IdentificationKey, ScannedText, RecordedText, RecordedOrganism, TaxonPage, MultimediaLearningObject, VirtualRealityEnvironment, GlossaryPage. These values may either be used in their literal form, or with their full namespace, e. g. http://rs.tdwg.org/ac/terms/identificationKey
Details
Comments:	This does not apply to Collection objects. The vocabulary may be extended by users provided they identify the term by a URI which is not in the ac namespace (for example, using "http://my.inst.org/namespace/metadata/subtype/repair-manual". Conforming applications may choose to ignore these.
Crosswalk:	DublinCore: dcterms:type — XMP: — DarwinCore: — NCD: Collection->collectionType — Morphbank: — LIFE: Type Details — K2N: k2n:Type pro parte — MIX2.0:
Term: dcterms:title
Normative URI:	http://purl.org/dc/terms/title
Label	Title
	Layer: Core — Required: Yes — Repeatable: default No
Definition:	Concise title, name, or brief descriptive label of institution, resource collection, or individual resource. This field should include the complete title with all the subtitles, if any.
Details	dcterms:title
Comments:	The title facilitates interactions with humans: e.g. the title could be used as display text of hyperlinks or to provide a choice of images in a pick list. The title is therefore highly useful and an effort should be made to provide it, where not already available. When the resource is a collection without an institutional or official name, but with a thematic content, a descriptive title, e. g. “Urban Ants of New England” would be suitable. In individual media resources depicting taxa, the scientific name or names of taxa often form a good title. Common names in addition to or instead of scientific names are also acceptable. Indications of action or roles captured by the media resource, such as predatory acts, are desirable (“Rattlesnake eating deer mouse”, “Pollinators of California Native Plants”).
Crosswalk:	DublinCore: — XMP: — DarwinCore: — NCD: dcterms:title — Morphbank: — LIFE: Title for media resource, or Collection Title for a collection, for Provider or institution it matches the Name/Roles pair combination — K2N: k2n:Title — MIX2.0:
Term: dcterms:modified
Normative URI:	http://purl.org/dc/terms/modified
Label	Modified
	Layer: Extended — Required: No — Repeatable: Yes
Definition:	Date that the media resource was altered. The date and time must comply with the World Wide Web Consortium (W3C) datetime practice, which requires that date and time representation correspond to ISO 8601:1998, but with year fields always comprising 4 digits. This makes datetime records compliant with 8601:2004. AC datetime values may also follow 8601:2004 for ranges by separating two IS0 8601 datetime fields by a solidus ("forward slash", '/'). See also the wikipedia IS0 8601 entry for further explanation and examples.
Details	dcterms:modified
Comments:	dcterms:modified permits all modification dates to be recorded, or if only one is recorded, it is assumed to be the latest.
Crosswalk:	DublinCore: Same as dcterms:modified — XMP: http://ns.adobe.com/xap/1.0/ModifyDate — DarwinCore: — NCD: dcterms:modified — Morphbank: — LIFE: Date Modified — K2N: k2n:Modified — MIX2.0: mix2:ChangeHistory/ImageProcessing/dateTimeProcessed
Term: xmp:MetadataDate
Normative URI:	http://ns.adobe.com/xap/1.0/MetadataDate
Label	Metadata Date
	Layer: Core — Required: No — Repeatable: No
Definition:	Point in time recording when the last modification to metadata (not necessarily the media object itself) occurred. The date and time must comply with the World Wide Web Consortium (W3C) datetime practice, which requires that date and time representation correspond to ISO 8601:1998, but with year fields always comprising 4 digits. This makes datetime records compliant with 8601:2004. AC datetime values may also follow 8601:2004 for ranges by separating two IS0 8601 datetime fields by a solidus ("forward slash", '/'). See also the wikipedia IS0 8601 entry for further explanation and examples.
Details	Terms for Adobe XMP have URIs that are not resolvable. Instead, visit , XMP Specification Part 1, Sec 8.4 for further documentation. Note that XMP does not have an explicit XML-Schema. Rather, an "XMP Schema" is actually defined in RDF.
Comments:	This is not dcterms:modified, which refers to the resource itself rather than its metadata. A use case is incremental harvesting: the holder of metadata who also holds the resources may be receiving metadata more frequently than the underlying resources; thus this date information may help a user harvesting the metadata to decide whether updating is necessary.
Crosswalk:	DublinCore: dcterms:modified referring to a "metadata resource". — XMP: http://ns.adobe.com/xap/1.0/MetadataDate. IPTC Extension 1.0 also provides IPTC Metadata Last Edited = http://iptc.org/std/Iptc4xmpExt/1.0/xmlns/IptcLastEdited - which, however, seem to be limited to modifications of IPTC fields alone. — DarwinCore: — NCD: dcterms:modified Collection->formationPeriod? — Morphbank: BaseObject.dateModified — LIFE: Date Record Modified — K2N: k2n:Metadata_Modified — MIX2.0:
Term: Metadata_Language
Normative URI:	http://rs.tdwg.org/ac/terms/metadataLanguage
Label	Metadata Language
	Layer: Core — Required: Yes — Repeatable: default No
Definition:	Language of description and other metadata (but not necessarily of the image itself) represented in ISO639-1 or -3.
Details
Comments:	This is NOT dcterms:language , which is about the resource, not the metadata. This is deliberately single-valued, imposing a requirement that multi-lingual metadata be represented as separate, complete, metadata records in which also the language-neutral items appear. Consumers can re-combine records by identity of multimedia Resource IDs (which are highly recommended to supply). In the face of metadata records of several languages for the same resource, this normative document offers no guidance as to how to disambiguate what language applies to what metadata. To disambiguate this, the metadata provider can provide a separate AC object for each different MetadataLanguage, each such AC object referring to the same multimedia resource Identifier. This comes at a cost of repeated data for the "language neutral" metadata items, but the alternative is to have a complex hierarchical structure for an AC object. Nothing in this document would prevent an implementer, e. g. of an XML-Schema representation, from providing a fully hierarchical schema and disambiguating that way. Users of particular implementation should consult documentation specific for that implementation on this point, but it should always be correct, if convenient, to provide one metadata record per language.
Crosswalk:	DublinCore: dcterms:language referring to a "metadata resource". — XMP: — DarwinCore: — NCD: — Morphbank: "English" — LIFE: Language of Cataloging — K2N: k2n:Metadata_Language — MIX2.0:
Term: Provider Managed ID
Normative URI:	http://rs.tdwg.org/ac/terms/providerManagedID
Label	Provider Managed ID
	Layer: Extended — Required: No — Repeatable: default No
Definition:	A free-form identifier (a simple number, an alphanumeric code, a URL, etc.) that is unique and meaningful primarily for the data provider.
Details
Comments:	Ideally, this would be a globally unique identifier (GUID), but the provider is encouraged to supply any form of identifier that simplifies communications on resources within the project and help to locate individual data items in the provider's data repositories. It is the provider's decision whether to expose this value or not.
Crosswalk:	DublinCore: — XMP: — DarwinCore: — NCD: ncd:collectionId — Morphbank: id — LIFE: NA — K2N: k2n:Resource_ID — MIX2.0:
Term: xmp:Rating
Normative URI:	http://ns.adobe.com/xap/1.0/Rating
Label	Rating
	Layer: Core — Required: No — Repeatable: No
Definition:	A rating of the media resources, provided by users or editors, with -1 defining “rejected”, “0” defining “unrated”, and “1” (worst) to “5” (best).
Details	Terms for Adobe XMP have URIs that are not resolvable. Instead, visit , XMP Specification Part 1, Sec 8.4 for further documentation. Note that XMP does not have an explicit XML-Schema. Rather, an "XMP Schema" is actually defined in RDF.
Comments:	The origin of the rating is not communicated. It may, e. g., be based on user feedback or on editorial ratings. If Rating is not present, a value of 0 may be assumed.
Crosswalk:	DublinCore: — XMP: http://ns.adobe.com/xap/1.0/Rating — DarwinCore: — NCD: — Morphbank: — LIFE: NA — K2N: k2n:Rating — MIX2.0:
Term: Comments
Normative URI:	http://rs.tdwg.org/ac/terms/comments
Label	Comments
	Layer: Extended — Required: No — Repeatable: Yes
Definition:	Any comment provided on the media resource, as free-form text. Best practice would also identify the commenter.
Details
Comments:	Comments may refer to the resource itself (e. g., asserting a taxon name or location of a biological subject in an image), or to the relation between resource and associated metadata (e. g., asserting that the taxon name given in metadata is false, without asserting a positive identification). There is a separate item for reviewer comments, which is defined more as an expert-level review.
Crosswalk:	DublinCore: — XMP: — DarwinCore: — NCD: ncd:note — Morphbank: — LIFE: Outside Comments — K2N: not available — MIX2.0:
Term: Reviewer
Normative URI:	http://rs.tdwg.org/ac/terms/reviewer
Label	Reviewer
	Layer: Extended — Required: No — Repeatable: default No
Definition:	If present, then resource is peer-reviewed, even if Reviewers Comments are lacking. The notation of whether an expert in the subject featured in the media has reviewed the media item or collection and approved its metadata description. Must display a name or the literal "anonymous" (= anonymously reviewed).
Details
Comments:	Provider is asserting they accept this review as competent.
Crosswalk:	DublinCore: — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: Peer Reviewed (may change our item name to Reviewer) — K2N: k2n:Reviewer_Names — MIX2.0:
Term: Reviewer Comments
Normative URI:	http://rs.tdwg.org/ac/terms/reviewerComments
Label	Reviewer Comments
	Layer: Extended — Required: No — Repeatable: Yes
Definition:	Any comment provided by a reviewer with expertise in the subject, as free-form text.
Details
Comments:	Reviewer Comments may refer to the resource itself (e. g., asserting a taxon name or location of a biological subject in an image), or to the relation between resource and associated metadata (e. g., asserting that the taxon name given in metadata is false, without asserting a positive identification). There is a separate item “Comments” for text from commenters of unrecorded expertise.
Crosswalk:	DublinCore: — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: PeerReviewerComments — K2N: k2n:Reviewer_Comments — MIX2.0:
Term: dcterms:available
Normative URI:	http://purl.org/dc/terms/available
Label	Date Available
	Layer: Extended — Required: No — Repeatable: default No
Definition:	The date (often a range) that the resource became or will become available. The date and time must comply with the World Wide Web Consortium (W3C) datetime practice, which requires that date and time representation correspond to ISO 8601:1998, but with year fields always comprising 4 digits. This makes datetime records compliant with 8601:2004. AC datetime values may also follow 8601:2004 for ranges by separating two IS0 8601 datetime fields by a solidus ("forward slash", '/'). See also the wikipedia IS0 8601 entry for further explanation and examples.
Details	dcterms:available
Comments:	A use case is, for example, that metadata, potentially including occurrence records, are published before even before the media are available, which are pending a formal publication elsewhere.
Crosswalk:	DublinCore: same as dcterms:available — XMP: — DarwinCore: — NCD: — Morphbank: dateToPublish — LIFE: Date Published — K2N: (not supported) — MIX2.0:

7 Attribution Vocabulary

Term: xmpRights:Owner
Normative URI:	http://ns.adobe.com/xap/1.0/rights/Owner
Label	Copyright Owner
	Layer: Core — Required: Yes — Repeatable: No
Definition:	The name of the owner of the copyright. 'Unknown' is an acceptable value.
Details	Terms for Adobe XMP have URIs that are not resolvable. Instead, visit , XMP Specification Part 1, Sec 8.5 for further documentation. Note that XMP does not have an explicit XML-Schema. Rather, an "XMP Schema" is actually defined in RDF.
Comments:	ALA uses dcterms:publisher for this purpose, but it seems doubtful that the publisher is by necessity the copyright owner. Copyright owner cannot be repeated (only a single owner is possible).
Crosswalk:	DublinCore: dcterms:rights or dcterms:rightsHolder — XMP: http://ns.adobe.com/xap/1.0/rights/Owner type bag ProperName, "An unordered array specifying the legal owner(s) of a resource". — Note: IPTC Extension 1.0: also has Copyright Owner, using plus:CopyrightOwner — DarwinCore: — NCD: — Morphbank: — LIFE: contained within Rights Statement = — K2N: k2n:Copyright_Owner — MIX2.0:
Term: dcterms:rights
Normative URI:	http://purl.org/dc/terms/rights
Label	Copyright Statement
	Layer: Core — Required: Yes — Repeatable: No
Definition:	Information about rights held in and over the resource. A full-text, readable copyright statement, as required by the national legislation of the copyright holder. On collections, this applies to all contained objects, unless the object itself has a different statement. Examples: “Copyright XY 2008, all rights reserved”, “© 2008 XY Museum” , "Public Domain." Do not place just the name of the copyright holder here!
Details	dcterms:rights
Comments:	This expresses rights over the media resource, not over the metadata text.
Crosswalk:	DublinCore: dcterms:rights — XMP: related boolean term: xmpRights:Marked type: Boolean, "Indicates that this is a rights-managed resource"; if this is false it indicates a resource in the public domain. — DarwinCore: — NCD: dcterms:rights — Morphbank: — LIFE: Rights — K2N: k2n:Copyright_Statement — MIX2.0:
Term: xmpRights:UsageTerms
Normative URI:	http://ns.adobe.com/xap/1.0/rights/UsageTerms
Label	License Terms
	Layer: Core — Required: No — Repeatable: No
Definition:	The license statement defining how resources may be used. Information on a collection applies to all contained objects unless the object has a different statement.
Details	Terms for Adobe XMP have URIs that are not resolvable. Instead, visit , XMP Specification Part 1, Sec 8.5 for further documentation. Note that XMP does not have an explicit XML-Schema. Rather, an "XMP Schema" is actually defined in RDF.
Comments:	Example: "Available under Creative Commons by-nc-sa 2.5 license". This also informs on the commercial availability of items. Buying an identification tool or media resource is essentially the purchase of an individual license. Examples for such License statements: “Available through bookstores” for a commercially published CD, in License; “Individual licenses available for purchase” for a high-resolution image (note that the medium or low resolution levels of the same image may be available under Creative Commons!)
Crosswalk:	DublinCore: dcterms:rights — XMP: — DarwinCore: — NCD: ncd:usageRestrictions — Morphbank: — LIFE: License Statement — K2N: k2n:License Statement — MIX2.0:
Term: xmpRights:WebStatement
Normative URI:	http://ns.adobe.com/xap/1.0/rights/WebStatement
Label	License URL
	Layer: Core — Required: No — Repeatable: No
Definition:	A URL defining or further elaborating on the license statement (e. g., a web page explaining the precise terms of use).
Details	Terms for Adobe XMP have URIs that are not resolvable. Instead, visit , XMP Specification Part 1, Sec 8.5 for further documentation. Note that XMP does not have an explicit XML-Schema. Rather, an "XMP Schema" is actually defined in RDF.
Comments:	The value of this field may provide a complete definition of the terms of use. For Creative Commons, the appropriate value is the URL of the defining Web page for the license. Example: http://creativecommons.org/licenses/by-nc-sa/3.0/us/. Where different quality variants (e. g. resolutions of images) are published under different licenses, the AC term “Licensing Exception Statement” supports variant-specific licenses.
Crosswalk:	DublinCore: dcterms:rights — XMP: xmpRights:WebStatement type: URL, defined as "The location of a web page describing the owner and/or rights statement for this resource." — DarwinCore: — NCD: ncd:usageRestrictions — Morphbank: value is contained in Image.creativeCommons — LIFE: License Statement — K2N: k2n:License_URL — MIX2.0:
Term: License Logo URL
Normative URI:	http://rs.tdwg.org/ac/terms/licenseLogoURL
Label	License Logo URL
	Layer: Core — Required: No — Repeatable: No
Definition:	A URL providing access to a logo that symbolizes the License.
Details
Comments:	The legal responsibility for choosing a correct graphical representation must lie with the provider of metadata and can not be assumed by a service that offers a search or reporting user-interface. Example:
Crosswalk:	DublinCore: dcterms:rights — XMP: — DarwinCore: — NCD: — Morphbank: value is contained in Image.creativeCommons — LIFE: NA (added service on top of license statement) — K2N: — MIX2.0:
Term: Attribution Statement
Normative URI:	http://iptc.org/std/Iptc4xmpExt/1.0/xmlns/CreditLine
Label	Attribution Statement
	Layer: Core — Required: No — Repeatable: No
Definition:	free text for "please cite this as…"
Details	IPTC terms for Adobe XMP have URIs that are not resolvable. Instead, visit IPTC Standard Photo Metadata (July 2010) for further documentation. Note that XMP does not have an explicit XML-Schema. Rather, an "XMP Schema" is actually defined in RDF.
Crosswalk:	Creative Commons with cc = http://creativecommons.org/ns# currently has the following properties: cc:attributionURL — "The URL to use when attributing this work" and cc:attributionName — "The creator's preferred name to use when attributing this work." — DublinCore: ? — XMP: — DarwinCore: — NCD: — Morphbank: info may be in Image.copyrightText — LIFE: Credit line — K2N: k2n:Credit Line — MIX2.0:
Term: Attribution Logo URL
Normative URI:	http://rs.tdwg.org/ac/terms/attributionLogoURL
Label	Attribution URL
	Layer: Core — Required: No — Repeatable: No
Definition:	The URL of icon or logo image to appear in source attribution.
Details
Comments:	Entering this URL into a browser should only result in the icon (not in a webpage including the icon).
Crosswalk:	DublinCore: — XMP: — DarwinCore: — NCD: — Morphbank: User.userLogo — LIFE: MODs name/role combination for Contributing Partner - added service on top of name — K2N: k2n:Attribution Link URL . K2N also has object logo, but defined as logo of resource (where a collection or institution is a resource. This does not apply here because of strict limitation to media. — MIX2.0:
Term: Attribution Link URL
Normative URI:	http://rs.tdwg.org/ac/terms/attributionLinkURL
Label	Attribution Link URL
	Layer: Core — Required: No — Repeatable: No
Definition:	The URL where information about ownership, attribution, etc. of the resource may be found.
Details
Comments:	This URL may be used in creating a clickable logo. Providers should consider making this link as specific and useful to consumers as possible, e. g., linking to a metadata page of the specific image resource rather than to a generic page describing the owner or provider of a resource.
Crosswalk:	DublinCore: — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: Resource identifier — K2N: k2n:Attribution Link URL — MIX2.0:
Term: dcterms:source
Normative URI:	http://purl.org/dc/terms/source
Label	Published Source
	Layer: Core — Required: No — Repeatable: Yes
Definition:	An identifiable source from which the described resources was derived. It may be digital, but in any case should be a source for which the originator intended long-term availability.
Details	dcterms:source
Comments:	If image, key, etc. was taken from (i.e. digitized) or was also published in a digital or printed publication. Do not put generally "related" publications in here. This field normally contains a free-form text description; it may be a URI: (“digitally-published://ISBN=961-90008-7-0”) if this resource is also described separately in the data exchange. Can be repeatable if a montage of images.
Crosswalk:	DublinCore: dcterms:source — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: Source — K2N: k2n:Published_Source — MIX2.0:

8 Agents Vocabulary

Term: dcterms:creator
Normative URI:	http://purl.org/dc/terms/creator
Label	Creator
	Layer: Core — Required: No — Repeatable: Yes
Definition:	The person or organization responsible for creating the media resource
Details	dcterms:creator
Comments:	* The value may be simple text including contact information. Note that the creator need not be the Copyright Owner
Crosswalk:	Morphbank = Image.photographer — DublinCore: dcterms:creator — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: MODS name/role Creator — K2N: k2n:Creators — MIX2.0:
Term: Provider
Normative URI:	http://rs.tdwg.org/ac/terms/provider
Label	Provider
	Layer: Core — Required: No — Repeatable: No
Definition:	Person or organization responsible for presenting the media resource. If no separate Metadata Provider is attributed, this attributes also the metadata.
Details
Comments:	Media items and Metadata may be served from different institutions, e. g. in the case of aggregators adding user annotations, taxon identifications, or ratings.
Crosswalk:	Derived from ISO NAP Metadata CI_ResponsibleParty — DublinCore: dcterms:creator — XMP: — DarwinCore: (InstitutionCode is closest match) — NCD: — Morphbank: Contributor (Image.userId) — LIFE: Mods Name/Role Contributing Partner — K2N: k2n:Service Attribution URI — MIX2.0:
Term: Metadata Provider
Normative URI:	http://rs.tdwg.org/ac/terms/metadataProvider
Label	Metadata Provider
	Layer: Core — Required: No — Repeatable: Yes
Definition:	Person or organization originally responsible for compiling and presenting providing the resource metadata record.
Details
Comments:	Media items and Metadata may be served from different institutions, e. g. in the case of aggregators adding user annotations, taxon identifications, or ratings. Compare Provider.
Crosswalk:	Derived from ISO NAP Metadata CI_ResponsibleParty — DublinCore: dcterms:creator — XMP: — DarwinCore: — NCD: — Morphbank: morphbank.net — LIFE: MODS name/role Metadata Contributor? — K2N: k2n:Metadata Provider — MIX2.0:
Term: Metadata Creator
Normative URI:	http://rs.tdwg.org/ac/terms/metadataCreator
Label	Metadata Creator
	Layer: Core — Required: No — Repeatable: Yes
Definition:	Person or organization originally creating the resource metadata record.
Details
Crosswalk:	Derived from ISO NAP Metadata CI_ResponsibleParty — DublinCore: dcterms:creator — XMP: — DarwinCore: — NCD: — Morphbank: morphbank.net — LIFE: MODS name/role Metadata Contributor? — K2N: k2n:Metadata Provider — MIX2.0:

9 Content Coverage Vocabulary

Term: dcterms:description
Normative URI:	http://purl.org/dc/terms/description
Label	Description
	Layer: Core — Required: No — Repeatable: No
Definition:	Description of collection or individual resource, containing the Who, What, When, Where and Why as free-form text. This normative document is silent on the nature of formatting in the text. It is the role of implementers of an AC concrete representation (e.g. an XML Schema, an RDF representation, etc.) to decide and document how formatting advice will be represented in Descriptions serialized according to such representations.
Details	dcterms:description
Comments:	It optionally allows to present detailed information and will in most cases be shown together with the resource title. If both description and caption (see below) are present, a description is typically displayed instead of the resource, a caption together with the resource. Should be a good proxy for the underlying media resource.
Crosswalk:	DublinCore: dcterms:description — XMP: — DarwinCore: — NCD: dcterms:description — Morphbank: description — LIFE: Description — K2N: k2n:Description — MIX2.0:
Term: Caption
Normative URI:	http://rs.tdwg.org/ac/terms/caption
Label	Caption
	Layer: Extended — Required: No — Repeatable: No
Definition:	As alternative or in addition to description, a caption is free-form text to be displayed together with (rather than instead of) a resource that is suitable for captions (especially images).
Details
Comments:	Often only one of description or caption is present; choose the concept most appropriate for your metadata.
Crosswalk:	DublinCore: dcterms:description — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: NA — K2N: k2n:Caption — MIX2.0:
Term: dcterms:language
Normative URI:	http://purl.org/dc/terms/language
Label	Language
	Layer: Core — Required: No — Repeatable: Yes
Definition:	Language(s) of resource itself represented in ISO639-1 or -3
Details	dcterms:language
Comments:	An image may contain language such as superimposed labels. If an image is of a natural scene or organism, without any language included, the resource is language-neutral (ISO code “zxx”). Resources with present but unknown language are to be coded as undetermined (ISO code “und”). Resources only containing scientific organism names should be coded as "zxx-x-taxon" (do not use the incorrect “la” for Latin). If there is no language code available, you must use the ISO extension mechanisms (x-XXX or XXXXXXX, CITE).
Crosswalk:	DublinCore: dcterms:language — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: language — K2N: k2n:Language — MIX2.0:

10 Geography Vocabulary

Location created and Location shown are separated in the current version of IPTC, and the metadata working group (MWG 2010) also recommends this. We will follow this, to support the expected future increase of automatic GPS based coordinate recording in recording devices. As a special case, the AC group recommends to change the semantics of location shown in the case of biodiversity specimens, where the original location may differ from the current location at which the specimen is held in a collection. In this case, LocationShown should exclusively refer to the location where a specimen was originally collected (gathering or sampling location). Use LocationCreated to express the location where the media was created (a specimen was digitized).

All geography terms from the DarwinCore version of 12 09 2009 are deemed included in the Core Layer. Specifically, this includes exactly those which are declared by DarwinCore to be in DarwinCore Class Location. Note that dwcterms:locality may be used, but as applied to media this term may be ambiguous as to whether it applies to the location depicted or the location at which the media was created. When disambiguating information is available, it is better to use the terms Location Shown and Location Acquired

Term: Location Shown
Normative URI:	http://iptc.org/std/Iptc4xmpExt/1.0/xmlns/LocationShown
Label	Location Shown
	Layer: Core — Required: No — Repeatable: Yes
Definition:	The location that is shown or the place of the media content, irrespective of the location from which the resource has been created.
Details	IPTC terms for Adobe XMP have URIs that are not resolvable. Instead, visit IPTC Standard Photo Metadata (July 2010) for further documentation. Note that XMP does not have an explicit XML-Schema. Rather, an "XMP Schema" is actually defined in RDF.
Crosswalk:	DublinCore: dcterms:coverage — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: — K2N: (K2N is flat and does not support classes) — MIX2.0:
Term: World Region
Normative URI:	http://iptc.org/std/Iptc4xmpExt/1.0/xmlns/WorldRegion
Label	World Region
	Layer: Core — Required: No — Repeatable: Yes
Definition:	Name of a world region in some high level classification, such as names for continents, waterbodies, or island groups, whichever is most appropriate. The terms preferably are derived from a controlled vocabulary (to be defined).
Details	IPTC terms for Adobe XMP have URIs that are not resolvable. Instead, visit IPTC Standard Photo Metadata (July 2010) for further documentation. Note that XMP does not have an explicit XML-Schema. Rather, an "XMP Schema" is actually defined in RDF.
Comments:	The equivalent DarwinCore fields here forces primary metadata providers to classify world region terms into separate properties for “continent” “waterbody”, “IslandGroup”. By contrast, the Iptc4xmpExt vocabulary only specifies that a World Region is something at the top of a hierarchy of locations.
Crosswalk:	DublinCore: dcterms:coverage — XMP: — DarwinCore: dwc:continent or dwc:waterbody or dwc:IslandGroup or dwc:island — NCD: — Morphbank: — LIFE: Continent/Ocean — K2N: k2n:World Region — MIX2.0:
Term: Country Code
Normative URI:	http://iptc.org/std/Iptc4xmpExt/1.0/xmlns/CountryCode
Label	Country Code
	Layer: Core — Required: No — Repeatable: Yes
Definition:	The geographic location of the specific entity(ies) documented by the media item, expressed through a constrained vocabulary of countries using 2-letter ISO country code (e. g. "it, si").
Details	IPTC terms for Adobe XMP have URIs that are not resolvable. Instead, visit IPTC Standard Photo Metadata (July 2010) for further documentation. Note that XMP does not have an explicit XML-Schema. Rather, an "XMP Schema" is actually defined in RDF.
Comments:	Accepted exceptions to be used instead of ISO codes are: "Global", "Marine", "Europe", “N-America”, “C-America”, “S-America”, "Africa", “Asia”, “Oceania”, ATA = "Antarctica", XEU = "European Union", XAR = "Arctic", "ZZZ" = "Unknown country" (3 letter abbreviations from IPTC codes). This list may be extended as necessary.
Crosswalk:	DublinCore: dcterms:coverage — XMP: — DarwinCore: dwc:countryCode — NCD: Collection->spatialCoverage? — Morphbank: — LIFE: Country? — K2N: k2n:Country_Codes — MIX2.0:
Term: Country Name
Normative URI:	http://iptc.org/std/Iptc4xmpExt/1.0/xmlns/CountryName
Label	Country Name
	Layer: Core — Required: No — Repeatable: Yes
Definition:	This field can be free text, but where possible, the use of http://iptc.org/std/Iptc4xmpExt/1.0/xmlns/CountryCode is preferred.
Details	IPTC terms for Adobe XMP have URIs that are not resolvable. Instead, visit IPTC Standard Photo Metadata (July 2010) for further documentation. Note that XMP does not have an explicit XML-Schema. Rather, an "XMP Schema" is actually defined in RDF.
Crosswalk:	DublinCore: dcterms:coverage — XMP: — DarwinCore: dwc:country — NCD: — Morphbank: Locality.country — LIFE: Country — K2N: k2n:Country_Names — MIX2.0:
Term: Province or State
Normative URI:	http://iptc.org/std/Iptc4xmpExt/1.0/xmlns/ProvinceState
Label	Province or State
	Layer: Core — Required: No — Repeatable: Yes
Definition:	Optionally, the geographic unit immediately below the country level (individual states in federal countries, provinces, or other administrative units) in which the subject of the media resource (e. g., species, habitats, or events) were located (if such information is available in separate fields).
Details	IPTC terms for Adobe XMP have URIs that are not resolvable. Instead, visit IPTC Standard Photo Metadata (July 2010) for further documentation. Note that XMP does not have an explicit XML-Schema. Rather, an "XMP Schema" is actually defined in RDF.
Crosswalk:	DublinCore: dcterms:coverage — XMP: — DarwinCore: dwc:stateProvince — NCD: Collection->spatialCoverage? — Morphbank: Locality.state — LIFE: state or province — K2N: k2n:State_or_Province — MIX2.0:
Term: City or Place Name
Normative URI:	http://iptc.org/std/Iptc4xmpExt/1.0/xmlns/City
Label	City or Place Name
	Layer: Extended — Required: No — Repeatable: Yes
Definition:	Optionally, the name of a city or place commonly found in gazetteers (such as a mountain or national park) in which the subjects (e. g., species, habitats, or events) were located.
Details	IPTC terms for Adobe XMP have URIs that are not resolvable. Instead, visit IPTC Standard Photo Metadata (July 2010) for further documentation. Note that XMP does not have an explicit XML-Schema. Rather, an "XMP Schema" is actually defined in RDF.
Crosswalk:	DublinCore: dcterms:coverage — XMP: — DarwinCore: (no equivalent in DarwinCore seems to exist) — NCD: Collection->spatialCoverage? — Morphbank: — LIFE: city or place name — K2N: k2n:City or Place Name — MIX2.0:
Term: Sublocation
Normative URI:	http://iptc.org/std/Iptc4xmpExt/1.0/xmlns/Sublocation
Label	Sublocation
	Layer: Core — Required: No — Repeatable: Yes
Definition:	Free-form text location details of the location of the subjects, down to the village, forest, or geographic feature etc., below the city or other place name, especially information that could not be found in a gazetteer.
Details	IPTC terms for Adobe XMP have URIs that are not resolvable. Instead, visit IPTC Standard Photo Metadata (July 2010) for further documentation. Note that XMP does not have an explicit XML-Schema. Rather, an "XMP Schema" is actually defined in RDF.
Comments:	We distinguish Locality in the sense of dwc (= a complete description of a locality, with the possible exception of country names etc., which can be separated into dwc:HigherGeography), and Sublocation in the sense of IPTC/XMP, i.e. the further details below a city or other place name, of a free-form text location within a fully hierarchically arranged grouping (earlier IPTC versions used “Location”, but this has been renamed as of 2008).
Crosswalk:	DublinCore: dcterms:coverage — XMP: — DarwinCore: related to dwc:location, but dwc:location may be a complete location, while sublocation is the remainder in a hierarchy — NCD: — Morphbank: — LIFE: Locality — K2N: (not supported, compare Location) — MIX2.0:

11 Temporal Coverage Vocabulary

Term: dcterms:temporal
Normative URI:	dcterms:temporal
Label	Temporal Coverage
	Layer: Extended — Required: No — Repeatable: default No
Definition:	The coverage (extent or scope) of the content of the resource. Temporal coverage will typically include temporal period (a period label, date, or date range) to which the subjects of the media or media collection relate. If dates are mentioned, they should follow ISO 8601. When the resource is a Collection, this refers to the temporal coverage of the collection.
Details	dcterms:temporal
Comments:	Examples in English: "Jurassic", "Elizabethan", "Spring, 1957". 2008-01-01/2008-06-30. If the resource is video or audio, it refers to the time span, if any, depicted by the resource. For live-media this is closely related to Creation Date and time (Example: the time depicted by a time-lapse video file of organism development), but for media with fictional content it is not.
Crosswalk:	DublinCore: dcterms:temporal — XMP: — DarwinCore: dwc:earliestDateCollected and dwc:latestestDateCollected — NCD: ncd:temporalCoverage — Morphbank: — LIFE: Temporal Coverage — K2N: not available yet — MIX2.0:
Term: Original Date and Time
Normative URI:	http://ns.adobe.com/xap/1.0/CreateDate
Label	Original Date and Time
	Layer: Core — Required: No — Repeatable: No
Definition:	The date of the creation for the original resource from which the digital media was derived or created. The date and time must comply with the World Wide Web Consortium (W3C) datetime practice, which requires that date and time representation correspond to ISO 8601:1998, but with year fields always comprising 4 digits. This makes datetime records compliant with 8601:2004. AC datetime values may also follow 8601:2004 for ranges by separating two IS0 8601 datetime fields by a solidus ("forward slash", '/'). See also the wikipedia IS0 8601 entry for further explanation and examples.
Details	Terms for Adobe XMP have URIs that are not resolvable. Instead, visit , XMP Specification Part 1, Sec 8.4 for further documentation. Note that XMP does not have an explicit XML-Schema. Rather, an "XMP Schema" is actually defined in RDF.
Comments:	What is what constitutes "original" is determined by the metadata author. Example: Digitization of a photographic slide of a map would normally give the date at which the map was created; however a photographic work of art including the same map as its content may give the date of the original photographic exposure. Imprecise or unknown dates can be represented as ISO dates or ranges. Compare also Date and Time Digitized. Is this redundant? BobMorris 18:31, 1 February 2009 (CEST)
Crosswalk:	DublinCore: dcterms:date — XMP: — DarwinCore: — NCD: Collection->temporalCoverage? — Morphbank: — LIFE: Date Original — K2N: k2n:Original_Creation_Date — MIX2.0:
Term: Time of Day
Normative URI:	http://rs.tdwg.org/ac/terms/timeOfDay
Label	Time of Day
	Layer: Core — Required: No — Repeatable: No
Definition:	Free text information beyond exact clock times.
Details
Comments:	Examples in English: afternoon, twilight.
Crosswalk:	DublinCore: dcterms:date — XMP: — DarwinCore: dwc:startTimeOfday and dwc:endTimeOfDay — NCD: — Morphbank: — LIFE: Time of Day — K2N: (not available) — MIX2.0:

12 Subject of Resource Vocabulary

Term: Physical Setting
Normative URI:	http://rs.tdwg.org/ac/terms/physicalSetting
Label	Physical Setting
	Layer: Extended — Required: No — Repeatable: Yes
Definition:	The Setting of the content represented in a medium like images, sounds, movies. Constrained vocabulary of: "Natural" = Unmodified object in a natural setting of unmodified object (e. g. living organisms in their natural environment); "Artificial" = Unmodified object in artificial setting of (e. g. living organisms in artificial environment: Zoo, Garden, Greenhouse, Laboratory; photographic background or background sound suppression). "Irrelevant" (e. g. background of Museum shots).
Details
Comments:	Multiple values may be needed for movies.
Crosswalk:	DublinCore: dcterms:subject — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: Nature of Content (in part) — K2N: — MIX2.0:
Term: Subject Category
Normative URI:	http://iptc.org/std/Iptc4xmpExt/1.0/xmlns/CVterm
Label	Subject Category
	Layer: Core — Required: No — Repeatable: Yes
Definition:	Controlled vocabulary of subjects to support broad classification of media items. Terms from various controlled vocabularies may be used. AC-recommended vocabularies are preferred and may be unqualified literals (without a URI). For terms from other vocabularies either a precise URI should be used, or, when providing unqualified terms, to provide the source vocabulary in Subject Category Vocabulary.
Details	IPTC terms for Adobe XMP have URIs that are not resolvable. Instead, visit IPTC Standard Photo Metadata (July 2010) for further documentation. Note that XMP does not have an explicit XML-Schema. Rather, an "XMP Schema" is actually defined in RDF.
Comments:	Recommended sets include: tha NASA Global Change Master Directory (GCMD) , K2N , the BioComplexity Thesaurus, and the European Environmental Agency GEneral Multilingual Environmental Thesaurus(GEMET) . The vocabulary may include major taxonomic groups (such as “vertebrates” or “fungi”) or ecosystem terms (“savannah”, “temperate rain forest”, “forest fires”, “aquatic vertebrates”). Other formal classifications (published in print or online) such as habitat, fuel, invasive species, agroproductivity, fisheries, migratory species etc. also can are also suitable.
Crosswalk:	DublinCore: dcterms:subject — XMP: — DarwinCore: — NCD: Collection->taxonCoverage? — Morphbank: — LIFE: Controlled subject; Formal Classification — K2N: k2n:Subject Category — MIX2.0:
Term: Subject Category Vocabulary
Normative URI:	http://rs.tdwg.org/ac/terms/subjectCategoryVocabulary
Label	Subject Category Vocabulary
	Layer: Extended — Required: No — Repeatable: Yes
Definition:	Any vocabulary or formal classification from which terms in Subject Category have been drawn.
Details
Comments:	The AC recommended vocabularies do not need to be cited here. There is no linkage between individual Subject Category terms and the vocabulary; the mechanism is intended to support discovery of the normative URI for a term, but not guarantee it.
Crosswalk:	DublinCore: dcterms:subject — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: Formal Classification Source (plus the BioComplexity Thesaurus) — K2N: not available — MIX2.0:
Term: Tag
Normative URI:	http://rs.tdwg.org/ac/terms/tag
Label	Tag
	Layer: Core — Required: No — Repeatable: Yes
Definition:	General keywords or tags.
Details
Comments:	Tags may be multi-worded phrases. Where scientific names, common names, geographic locations, etc. are separable, these should go into the more specific metadata items provided further below. Examples: "flower diagram". Character or part keywords like "leaf", "flower color" are especially desirable.
Crosswalk:	DublinCore: dcterms:subject — XMP: — DarwinCore: — NCD: — Morphbank: View.specimenPart — LIFE: Uncontrolled Subject — K2N: k2n:General Keywords — MIX2.0:

13 Taxonomic Coverage Vocabulary

Term: Taxon Coverage
Normative URI:	ncd:taxonCoverage
Label	Taxon Coverage
	Layer: Core — Required: No — Repeatable: No
Definition:	A higher taxon (e. g., a genus, family, or order) at the level of the genus or higher, that covers all taxa that are the primary subject of the resource (which may be a media item or a collection).
Details
Comments:	Example: Where the subject of an image is several species of ducks with trees visible in the background, Taxon Coverage would still be Anatidae (and not Biota). Example: “Aves” for a bird key or a bird image collection. Do not add a rank (“Class Aves”) in this field. Note that this somewhat expands the usage of ncd:taxonCoverage, which specifies at the Family level or higher. For collections it is recommended to follow ncd:taxonCoverage to avoid conflicts between an AC record and a record arising from NCD. If the resource contains a single taxon, this should be placed in Scientific Name. In this case Taxon Coverage may be left empty, but if not, care should be taken that the entries do not conflict. Example: If Scientific Name is Quercus alba then Taxon Coverage, if provided at all, should be Quercus.
Crosswalk:	DublinCore: dcterms:subject (not coverage!) — XMP: — DarwinCore: — NCD: ncd:taxonCoverage — Morphbank: Specimen.scientificName — LIFE: NA — K2N: k2n:Taxonomic Coverage — MIX2.0:
Term: dwc:scientificName
Normative URI:	http://rs.tdwg.org/dwc/terms/taxonName
Label	Taxon Name
	Layer: Core — Required: No — Repeatable: Yes
Definition:	Taxon names of organisms represented in the media resource (with date and authorship information if available) of the lowest level taxonomic rank that can be applied.
Details	dwc:taxonName
Comments:	The Taxon Name may possibly be a Genus or Family name, if this is the most specific identification available. Where multiple taxa are the subject, multiple names may be given. If possible, add this information here even if the title or caption of the resource already contains scientific names. Where the list of scientific names is impractically large (e. g., media collections or identification tools), the number of taxa should be given in Taxon Count (see below). If possible, please do not repeat the Taxonomic Coverage here. Do not use abbreviated Genus names ("P. vulgaris"). It is recommended to provide author citation to scientific names, to avoid ambiguities in the presence of homonyms (the same name created by different authors for different taxa). Identifier qualifications should be supplied in the Identification Qualifier term rather than here (i. e. “Abies cf. alba” is deprecated, to be replaced with Scientific Name = “Abies cf. alba” and Identification Qualifier = “cf.”).
Crosswalk:	DublinCore: dcterms:subject — XMP: — DarwinCore: dwc:scientificName — NCD: Collection->taxonCoverage? — Morphbank: Specimen.scientificName — LIFE: Scientific Name — K2N: k2n:Scientific Names — MIX2.0:
Term: dwc:identificationQualifier
Normative URI:	http://rs.tdwg.org/dwc/terms/identificationQualifier
Label	Identification Qualifier
	Layer: Core — Required: No — Repeatable: Yes
Definition:	A brief phrase or a standard abbreviation ("cf. genus", "cf. species", "cf. var.", "aff. species", etc.) to express the determiner's doubts about the identification given in Scientific Name.
Details	dwc:identificationQualifier
Comments:	Examples: 1) For the determinations “cf. Quercus agrifolia var. oxyadenia”, “Quercus cf. agrifolia var. oxyadenia”, “Quercus agrifolia cf. var. oxyadenia”, Scientific Name would always be “Quercus agrifolia var. oxyadenia”, with Identification Qualifier “cf. genus”, “cf. species” and “cf. var.”, respectively. For discussion of Darwin Core usage see http://code.google.com/p/darwincore/wiki/Identification
Crosswalk:	DublinCore: — XMP: — DarwinCore: dwc:identificationQualifier — NCD: — Morphbank: — LIFE: — K2N: — MIX2.0:
Term: dwc:vernacularName
Normative URI:	http://rs.tdwg.org/dwc/terms/vernacularName
Label	Common Name
	Layer: Core — Required: No — Repeatable: Yes
Definition:	Common (= vernacular) names of the subject in one or several languages. The ISO language name should be given in parentheses after the name if not all names are in Metadata Language.
Details	dwc:vernacularName
Comments:	Applicable only if the resource relates to a single taxon. The ISO language codes after the name should be formatted as in the following example: 'abete bianco (it); Tanne (de); White Fir (en)'. If names are known to be male- or female-specific, this may be specified as in: 'ewe (en-female); ram (en-male);'.
Crosswalk:	DublinCore: dcterms:subject — XMP: — DarwinCore: — NCD: ncd:commonNameCoverage — Morphbank: — LIFE: Common Name — K2N: k2n:Common Names — MIX2.0:
Term: dwc:nameAccordingTo
Normative URI:	http://rs.tdwg.org/dwc/terms/nameAccordingTo
Label	{{{Label}}}
	Layer: Extended — Required: No — Repeatable: Yes
Definition:	The taxonomic authority used to apply the name to the taxon, e. g., a book or web service from which the name comes from.
Details	dwc:nameAccordingTo
Comments:	Examples are "ITIS", "Catalogue of Life", "Peterson's guide for birds".
Crosswalk:	DublinCore: dcterms:subject — XMP: — DarwinCore: dwc:taxonAccordingTo — NCD: — Morphbank: Tree.nameSource — LIFE: Scientific Name Source — K2N: not supported — MIX2.0:
Term: dwc:taxonID
Normative URI:	http://rs.tdwg.org/dwc/terms/taxonID
Label	Scientific Name GUID
	Layer: Extended — Required: No — Repeatable: Yes
Definition:	Equivalent to Scientific Name, but using GUIDs such as http URIs or LSIDs to refer to the taxon names or concepts.
Details	dwc:taxonID
Crosswalk:	DublinCore: dcterms:subject — XMP: — DarwinCore: dwc:taxonID — NCD: — Morphbank: Tree.tsn — LIFE: TSN — K2N: not supported — MIX2.0:
Term: Scientific Name Synonym
Normative URI:	http://rs.tdwg.org/ac/terms/scientificNameSynonym
Label	Scientific Name Synonym
	Layer: Extended — Required: No — Repeatable: Yes
Definition:	One or several scientific names that are synonyms to the Scientific Name may be provided here.
Details
Comments:	The primary purpose of this is in support of resource discovery, not developing a taxonomic synonymy. Misidentification or misspellings may thus be of interest. Where multiple taxa are present in a resource and multiple Scientific Names are given, the association between synonym and name is not discoverable.
Crosswalk:	DublinCore: dcterms:subject — XMP: — DarwinCore: (implemented through record relations and TaxonomicStatus) — NCD: — Morphbank: — LIFE: NA — K2N: k2n:Scientific Name Synonyms — MIX2.0:
Term: dwc:identifiedBy
Normative URI:	http://rs.tdwg.org/dwc/terms/identifiedBy
Label	Identified By
	Layer: Extended — Required: No — Repeatable: Yes
Definition:	The name(s) of the person(s) who applied the Scientific Name to the sample.
Details	dwc:identifiedBy
Crosswalk:	DublinCore: — XMP: — DarwinCore: dwc:identifiedBy — NCD: — Morphbank: Specimen.name — LIFE: NA — K2N: k2n:Identified By — MIX2.0:
Term: dwc:dateIdentified
Normative URI:	http://rs.tdwg.org/dwc/terms/dateIdentified
Label	Date Identified
	Layer: Extended — Required: No — Repeatable: No
Definition:	The date on which the person(s) given under Identfied By applied a Scientific Name to the resource.
Details	dwc:dateIndentified
Comments:	What happens if there is more than 1 taxon on the media resource? --BobMorris 18:50,30 February 2010 (CEST)
Crosswalk:	DublinCore: — XMP: — DarwinCore: dwc:dateIdentified — NCD: — Morphbank: Specimen.dateIdentified — LIFE: NA — K2N: not available — MIX2.0:
Term: Taxon Count
Normative URI:	http://rs.tdwg.org/ac/terms/taxonCount
Label	Taxon Count
	Layer: Core — Required: No — Repeatable: No
Definition:	An exact or estimated number of taxa at the lowest applicable taxon rank (usually species or infraspecific) represented by the media resource (item or collection).
Details
Comments:	Primarily intended for resource collections and singular resources dealing with sets of taxa (e. g., identification tools, videos). It is recommended to give an exact or estimated number of specific taxa when a complete list of taxa is not available or practical. The count should contain only the taxa covered fully or primarily by the resource. For a taxon page and most images this will be “1”, i. e. other taxa mentioned on the side or in the background should not be counted. However, sometimes a resource may illustrate an ecological or behavioral entity with multiple species, e. g., a host-pathogen interaction; taxon count would then indicate the known number of species in this interaction. This should be a single integer number. Leave the field empty if you cannot estimate the information (do not enter 0). Additional taxon counts at higher levels (e. g. how many families are covered by a digital Fauna) should be given verbatim in the resource description, not here.
Crosswalk:	DublinCore: dcterms:subject — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: NA — K2N: k2n:Taxon Count — MIX2.0:
Term: Subject Part
Normative URI:	http://rs.tdwg.org/ac/terms/subjectPart
Label	Subject Part
	Layer: Extended — Required: No — Repeatable: Yes
Definition:	The portion of the organism, environment, etc. shown or particularly well illustrated.
Details
Comments:	No formal encoding scheme as yet exists. Examples are "whole body", "head", "flower", "leaf", "canopy" (of a rain forest stand). See comment in discussion below about a nascent encoding scheme.--Steve Baskauf 16:42, 30 April 2009 (CEST)
Crosswalk:	DublinCore: dcterms:subject — XMP: — DarwinCore: — NCD: — Morphbank: View.specimenPart — LIFE: Part of Subject — K2N: k2n:Subject Part — MIX2.0:
Term: Subject Sex
Normative URI:	dwc:sex
Label	Subject Sex
	Layer: Extended — Required: No — Repeatable: Yes
Definition:	A description of the sex of any organisms featured within the media, when relevant to the subject of the media, e. g., male, female, hermaphrodite, dioecious.
Details
Crosswalk:	DublinCore: dcterms:subject — XMP: — DarwinCore: dwc:Sex — NCD: — Morphbank: Specimen.sex, View.sex — LIFE: Sex — K2N: k2n:Subject Sex — MIX2.0:
Term: dwc:lifeStage
Normative URI:	http://rs.tdwg.org/dwc/terms/lifeStage
Label	Subject Life Stage
	Layer: Extended — Required: No — Repeatable: Yes
Definition:	A description of the life-cycle stage of any organisms featured within the media, when relevant to the subject of the media, e. g., larvae, juvenile, adult.
Details	dwc:lifeStage
Crosswalk:	DublinCore: dcterms:subject — XMP: — DarwinCore: dwc:lifeStage — NCD: — Morphbank: Specimen.developmentalStage, View.developmentalStage — LIFE: Stage — K2N: k2n:Subject Life Stage — MIX2.0:
Term: Subject Orientation
Normative URI:	http://rs.tdwg.org/ac/terms/subjectOrientation
Label	Subject Orientation
	Layer: Extended — Required: No — Repeatable: default No
Definition:	Specific orientiation (= direction, view angle) of the subject represented in the media resource with respect to the acquisition device.
Details
Comments:	Examples: "dorsal", "ventral", "frontal", etc. No formal encoding scheme as yet exists.
Crosswalk:	DublinCore: dcterms:subject — XMP: — DarwinCore: — NCD: — Morphbank: View.viewAngle — LIFE: View of Subject — K2N: k2n:Subject Orientation — MIX2.0: mix2:ImageCaptureMedadata/orientation
Term: dwc:preparations
Normative URI:	http://rs.tdwg.org/dwc/terms/preparations
Label	Subject Preparation Technique
	Layer: Extended — Required: No — Repeatable: default No
Definition:	Free form text describing the techniques used to prepare the subject of the media, prior to or while creating the media resource.
Details	dwc:preparations
Comments:	Examples for such techniques are: Insect under CO2, cooled to immobility, preservation with ethanol or formaldehyde. See also Resource Creation Technique for technical aspects of digital media object creation.
Crosswalk:	DWC= dwc:preparations — DublinCore: — XMP: — DarwinCore: — NCD: — Morphbank: View.imagingPreparationTechnique and maybe Specimen.preparationTechnique — LIFE: Comments on Collection; Capture Details — K2N: k2n:Creation Technique — MIX2.0:

14 Resource Creation Vocabulary

Term: Location Created
Normative URI:	http://iptc.org/std/Iptc4xmpExt/1.0/xmlns/LocationCreated
Label	Location Created
	Layer: Core — Required: No — Repeatable: Yes
Definition:	The location at which the media recording instrument was placed when the media was created.
Details	IPTC terms for Adobe XMP have URIs that are not resolvable. Instead, visit IPTC Standard Photo Metadata (July 2010) for further documentation. Note that XMP does not have an explicit XML-Schema. Rather, an "XMP Schema" is actually defined in RDF.
Comments:	The distinction between location shown and created is often irrelevant, and metadata may be assumed to be referring to location shown. It is recommended that the Location Shown field above always be used when known. However, in the case of position data automatically recorded by the instrument (e. g. EXIF GPS data) Location Created should be used to maintain information accuracy. When one but not both of Location Shown and Location Created are present, AC is silent about whether the provided one entails the other. A best practices document for a particular AC implementation might address this.
Crosswalk:	DublinCore: dcterms:coverage — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: — K2N: (K2N is flat and does not support classes) — MIX2.0:
Term: Date and Time Digitized
Normative URI:	http://rs.tdwg.org/ac/terms/digitizationDate
Label	Date and Time Digitized
	Layer: Extended — Required: No — Repeatable: No
Definition:	Date the first digital version was created, where different Date and Time Original (e. g. where photographic prints have been scanned). The date and time must comply with the World Wide Web Consortium (W3C) datetime practice, which requires that date and time representation correspond to ISO 8601:1998, but with year fields always comprising 4 digits. This makes datetime records compliant with 8601:2004. AC datetime values may also follow 8601:2004 for ranges by separating two IS0 8601 datetime fields by a solidus ("forward slash", '/'). See also the wikipedia IS0 8601 entry for further explanation and examples.
Details
Comments:	This is often not the file creation or modification date. Use the international (ISO/xml) format yyyy-mm-ddThh:mm (e. g. "2007-12-31" or "2007-12-31T14:59"). Where available, timezone information should be added. In the case of digital images containing EXIF, whereas the exif capture date does not contain time zone information, exif GPSDateStamp and GPSTimeStamp may be relevant as these include time-zone information. Compare also MWG (2010), which has best practice on handling time-zone-less EXIF date/time data.
Crosswalk:	For digital cameras, this maps to the exif capture date — DublinCore: — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: Date Digital — K2N: k2n:Digitization_Date — MIX2.0: mix2:ImageCaptureMetadata/GeneralCaptureInformation/dateTimeCreated
Term: Capture Device
Normative URI:	http://rs.tdwg.org/ac/terms/captureDevice
Label	Capture Device
	Layer: Extended — Required: No — Repeatable: No
Definition:	Free form text describing the device or devices used to create the resource.
Details
Comments:	It is best practice to record the device; this may include a combination such as camera plus lens, or camera plus microscope. Examples: "Canon Supershot 2000", "Makroscan Scanner 2000", "Zeiss Axioscope with Camera IIIu", "SEM (Scanning Electron Microscope)".
Crosswalk:	DublinCore: — XMP: — DarwinCore: — NCD: — Morphbank: View.imagingTechnique — LIFE: capture device, capture detail — K2N: — MIX2.0:
Term: Resource Creation Technique
Normative URI:	http://rs.tdwg.org/ac/terms/resourceCreationTechnique
Label	Resource Creation Technique
	Layer: Extended — Required: No — Repeatable: No
Definition:	Information about technical aspects of the creation and digitization process of the resource. This includes modification steps ("retouching") after the initial resource capture.
Details
Comments:	Examples: Encoding method or settings, numbers of channels, lighting, audio sampling rate, frames per second, data rate, interlaced or progressive, multiflash lighting, remote control, automatic interval exposure. Annotating whether and how a resource has been modified or edited significantly in ways that are not immediately obvious or expected to consumers is of special significance. Examples for images are: Removing a distracting twig from a picture, moving an object to a different surrounding, changing the color in parts of the image, or blurring the background of an image. Modifications that are standard practice and expected or obvious to users are not necessary to document; examples of such expected include changing resolution, cropping, minor sharpening or overall color correction, clearly perceptable modifications (adding arrows or labels, combination or multiple pictures into a table. If it is only known that significant modifications were made, but no details are known, a general statement like “Media may have been manipulated to improve appearance” may be appropriate. See also Subject Preparation Technique.
Crosswalk:	DublinCore: dcterms:description — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: Digitization Technique — K2N: replace this — MIX2.0: mix2:ImageCaptureMetadata/methodology

15 Service Access Point Vocabulary

See Discussion at ServiceAccessPoint especially as to whether Class structure is correct. --BobMorris 04:10, 15 August 2009 (CEST)

15.1 ServiceAccessPoint Class

Term: Access Point
Normative URI:	http://rs.tdwg.org/ac/terms/hasServiceAccessPoint
Label	Service Access Point
	Layer: Core — Required: No — Repeatable: Yes
Definition:	reference to an instance of a class describing network access to the media resource, or related resources, that the metadata describes. What constitutes a class is dependent on the representation (i.e. XML Schema, RDF, etc.)
Details
Comments:	Use with the properties below. In particular, there is little point to having an instance of this class without a value for the Access URL and perhaps the Format. Implementers in specific constraint languages such as XML Schema or OWL may wish to make those two properties mandatory on instances.
Crosswalk:	DublinCore: — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: — K2N: — MIX2.0:

15.2 Service Access Point Properties

Term: Access URL
Normative URI:	http://rs.tdwg.org/ac/terms/accessURL
Label	Access URL
	Layer: Core — Required: No — Repeatable: default No
Definition:	URL of the resource itself. If this resource can be acquired by an http request, its http URL should be given. If not, but it has some URI in another URI scheme, that may be given here.
Details
Comments:	For individual resources only. Use this field if only one quality level is available (as it is typical for taxon pages or keys!) Value might point to something offline, such as a published CD, etc. For example, the doi of an published CD would be a suitable
Crosswalk:	DublinCore: — XMP: — DarwinCore: — NCD: — Morphbank: http://www.morphbank.net/?id=XX&imgType=orig — LIFE: Resource ID, (QualityLevel)URL — K2N: (QualityLevel)URL — MIX2.0:
Term: Format
Normative URI:	dcterms:format
Label	Format
	Layer: Core — Required: No — Repeatable: No
Definition:	The technical format of the resource (file format or physical medium).
Details	dcterms:format
Comments:	Recommended best practice is to use a controlled vocabulary such as the list of Internet Media Types [MIME]. This item is recommended for offline digital content. In cases where the provided URL includes a standard file extension from which the format can be inferred it is permissible to not provide this item. Three types of values are acceptable: (a) any MIME type; (b) common file extensions like txt, doc, odf, jpg/jpeg, png, pdf; (c) the following special values: Data-CD, Audio-CD, Video-CD, Data-DVD, Audio-DVD, Video-DVD-PAL, Video-DVD-NTSC, photographic slide, photographic print. Compare Type for the content-type.
Crosswalk:	DublinCore: — XMP: — DarwinCore: — NCD: ncd:digitalFormat or ncd:digitalMedium — Morphbank: Image.imageType — LIFE: File Format — K2N: (QualityLevel) Format — MIX2.0:
Term: Variant
Normative URI:	http://rs.tdwg.org/ac/terms/variant
Label	Variant
	Layer: Core — Required: No — Repeatable: Yes
Definition:	What this ServiceAccessPoint provides. Permitted values are "Thumbnail", "Trailer", "Lower Quality", "Medium Quality", "Good Quality", "Best Quality", "Offline"
Details
Comments:	*Thumbnail: ServiceAccessPoint provides a thumbnail image, short sound clip, or short movie clip that can be used to represent the media object, typically at lower quality and higher compression than the preview object. A typical size for a tiny thumbnail image may be 50-100 pixels in the longer dimension. Trailer: ServiceAccessPoint provides video clip preview, in the form of a specifically authored "Trailer", which may provider somewhat different content than the original resource Lower Quality: ServiceAccessPoint provides a lower quality version of the media resource, suitable e. g. for web sites. Medium Quality: ServiceAccessPoint provides a medium quality version of the media resource, e. g. shortened in duration, or reduced size, using lower resolution or higher compression causing moderate artifacts. Good Quality: ServiceAccessPoint provides a good quality version of the media resource intended for resources displayed as primary information; e. g. an image between 800 and 1600 px in width or height. Best Quality: ServiceAccessPoint provides the highest available quality of the media resource, whatever its resolution or quality level. Offline: ServiceAccessPoint provides data about an offline resource.
Crosswalk:	DublinCore: — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: — K2N: — MIX2.0:
Term: Extent
Normative URI:	dcterms:extent
Label	Extent
	Layer: Extended — Required: No — Repeatable: No
Definition:	The size, dimensions, or duration of the variant of the media resource.
Details	dcterms:extent
Comments:	Best practices are: Extent as length/running time should use standard abbreviations of the metadata language (for English "20 s", "54 min"). Extent of images or video may be given as pixel size ("2000 x 1500 px"), or as file size (using kB, kByte, MB, MByte).
Crosswalk:	ORE:Extent — DublinCore: dcterms:extent (refines dcterms:format ) — XMP: — DarwinCore: — NCD: — Morphbank: Image.imageWidth, Image.imageHeight — LIFE: extent — K2N: (QualityLevel) Extent — MIX2.0: mix2:BasicImageInformation/BasicImageCharacteristics/imageWidth, and imageHeight
Term: Further Information URL
Normative URI:	http://rs.tdwg.org/ac/terms/furtherInformationURL
Label	Further Information URL
	Layer: Extended — Required: No — Repeatable: No
Definition:	The URL of a Web site that provides additional information about (this version of) the media resource
Details
Crosswalk:	DublinCore: — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: — K2N: under consideration — MIX2.0:
Term: Licensing Exception Statement
Normative URI:	http://rs.tdwg.org/ac/terms/licensingException
Label	Licensing Exception Statement
	Layer: Extended — Required: No — Repeatable: No
Definition:	The licensing statement for this variant of the media resource if different from that given in the “License Statement” property of the resource
Details
Comments:	Required only if this version has different licensing than that of the media resource. E. g. the highest resolution version may be more restricted than lower resolution versions
Crosswalk:	DublinCore: — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: — K2N: under consideration — MIX2.0:
Term: Service Expectation
Normative URI:	http://rs.tdwg.org/ac/terms/serviceExpectation
Label	Service Expectation
	Layer: Extended — Required: No — Repeatable: No
Definition:	A term that describes what service expectations users may have of the accessURL. Recommended terms include online (denotes that the URL is expected to deliver the resource), authenticate (denotes that the URL delivers a login or other authentication interface requiring completion before delivery of the resource) published(non digital) (denotes that the URL is the identifier of a non-digital published work, for example a doi.) Communities should develop their own controlled vocabularies for Service Expectations.
Details
Crosswalk:	DublinCore: — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: — K2N: Availability — MIX2.0:
Term: Variant Description
Normative URI:	http://rs.tdwg.org/ac/terms/variantDescription
Label	Variant Description
	Layer: Extended — Required: No — Repeatable: No
Definition:	Text that describes this Service Access Point variant
Details
Crosswalk:	DublinCore: — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: — K2N: considered detrimental, blurring the distinction between multiple (related) resources and versions of a single resource — MIX2.0:

16 Related Resources Vocabulary

Term: ID of Containing Collection
Normative URI:	http://rs.tdwg.org/ac/terms/IDofContainingCollection
Label	ID of Containing Collection
	Layer: Core — Required: No — Repeatable: default No
Definition:	If the resource is contained in a Collection, this field identifies that Collection uniquely. Its form is not specified by this normative document, but is left to implementers of specific implementations.
Details
Crosswalk:	DublinCore: dcterms:relation — XMP: — DarwinCore: — NCD: — Morphbank: URL for collection id, if present — LIFE: Other Related Resources (in part) — K2N: k2n:Collection Reference By ID — MIX2.0:
Term: Related Resource ID
Normative URI:	http://rs.tdwg.org/ac/terms/relatedResourceID
Label	Related Resource ID
	Layer: Extended — Required: No — Repeatable: default No
Definition:	Resource related in ways not specified through a collection. Before-after images Time-lapse series Different orientations/angles of view
Details
Crosswalk:	DublinCore: dcterms:relation — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: — K2N: none — MIX2.0:
Term: Provider ID
Normative URI:	http://rs.tdwg.org/ac/terms/providerID
Label	Provider ID
	Layer: Extended — Required: No — Repeatable: default No
Definition:	A globally unique ID of the provider of the current AC metadata record.
Details
Comments:	Only to be used if the annotated resource is not a provider itself - this item is for relating the resource to a provider, using an arbitrary code that is unique for a provider, contributing partner, or aggregator, or other roles (potentially defined by MARC, OAI) and by which the media resources are linked to the provider. -
Crosswalk:	DublinCore: dcterms:relation — XMP: — DarwinCore: — NCD: ncd:institutionId — Morphbank: URL for group — LIFE: see MARC Name/Roles - specific combinations — K2N: k2n:XXX — MIX2.0:
Term: Derived From
Normative URI:	http://rs.tdwg.org/ac/terms/derivedFrom
Label	Derived From
	Layer: Core — Required: No — Repeatable: Yes
Definition:	A reference to an original resource from which the current one is derived.
Details
Comments:	Derivation of one resource from another is of special interest for identification tools (e. g. a key from an unpublished data set, as in FRIDA, or a PDA key from a PC or web key) or web services (e. g. a name synonymization service being derived from a specific data set). It may very rarely also be known where one image or sound recording is derived from another (but compare the separate mechanism to be used for quality/resolution levels). – Human readable, or doi number, or URL.. Simple name of parent for human readable. Can be repeatedable if a montage of images.
Crosswalk:	DublinCore: dcterms:relation — XMP: xmpMM:, which however has a special document identifier scheme of document, instance and version IDs. — DarwinCore: — NCD: — Morphbank: — LIFE: Source, also Related Media — K2N: k2n:Derived_From — MIX2.0: mix2:ChangeHistory/ImageProcessing/sourceData
Term: Associated Specimen Reference
Normative URI:	http://rs.tdwg.org/ac/terms/associatedSpecimenReference
Label	Associated Specimen Reference
	Layer: Core — Required: No — Repeatable: default No
Definition:	a reference to a specimen associated with this resource.
Details
Comments:	Supports to find a specimen resource, where additional information is available. If several resources relate to the same specimen, these are implicitly related. Examples: for NHM “BM 23974324” for a barcoded or “BM Smith 32” for a non-barcoded specimen; for UNITS: “TSB 28637”; for PMSL: “PMSL-Lepidoptera-2534781”. Ideally this could be a URI identifying a specimen record that is online available.
Crosswalk:	DublinCore: dcterms:relation — XMP: — DarwinCore: — NCD: — Morphbank: Image.specimenId — LIFE: Specimen ID — K2N: k2n:XXX — MIX2.0:
Term: Associated Observation Reference
Normative URI:	http://rs.tdwg.org/ac/terms/associatedObservationReference
Label	Associated Observation Reference
	Layer: Core — Required: No — Repeatable: default No
Definition:	A reference to an observation associated with this resource.
Details
Crosswalk:	DublinCore: dcterms:relation — XMP: — DarwinCore: — NCD: — Morphbank: — LIFE: Other Related Resources — K2N: k2n:XXX — MIX2.0:

17 Controlled Vocabularies

In several cases AC requires or recommends controlled vocabularies. In addition to being referenced in the respective fields, we provide some links to analyses here.

• Audubon Core Summary of IPTC vocabularies

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