NLM Metadata Schema

(Approved February 2002)

(Revised July 29, 2004)

The NLM metadata schema is based on the metadata terms maintained by the Dublin Core Metadata Initiative, including elements, element refinements, encoding schemes, and vocabulary terms (cf. http://dublincore.org/documents/dcmi-terms/). It also incorporates some of the best practice recommendations of the DC-Library Application Profile (DC-Lib) (cf. http://dublincore.org/documents/2002/04/16/library-application-profile/). It is designed for use with electronic resources published by the Library and incorporates additional elements and qualifiers identified as requirements by NLM, most notably the addition of Permanence ratings for each resource. ¹

In the list which follows, the elements in the NLM Metadata schema are outlined using the following conventions:

The key used for "Identifier" is:

DC = Approved Dublin Core elements and qualifiers
NLMDC = Approved Dublin Core elements with NLM-defined qualifiers
NLM = NLM-defined elements

The key for the element requirements is:

R = Required
RA = Required if applicable
O = Optional

Element: Title

Name:        Title
Identifier:  DC.Title
Definition:  A name given to the resource
Required:    R
Repeatable:  N
Comments:    N/A

Element: Alternative Title

Name:        Alternative Title
Identifier:  DC.Title.Alternative
Definition:  Substitute or alternative names given to the resource,             
             including subtitles, acronyms, translations, etc.
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Subject, Keyword

Name:        Subject, Keyword
Identifier:  DC.Subject.Keyword
Definition:  Topic of the content of the resource
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Subject, MeSH

Name:        Subject, MeSH
Identifier:  DC.Subject.MeSH
Definition:  Topic of the content of the resource, expressed in
             NLM Medical Subject Headings
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Subject, Class Number

Name:        Subject, Class Number   
Identifier:  NLMDC.Subject.NLMClass
Definition:  An NLM classification number which represents the topic
             of the content of the resource
Required:    O
Repeatable:  N
Comments:    N/A

Element: Subject, Name

Name:        Subject, Name   
Identifier:  NLMDC.Subject.Name
Definition:  Personal or corporate names which represent the topic 
             of the content of the resource
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Subject, Title

Name:        Subject, Title   
Identifier:  NLMDC.Subject.Title
Definition:  Title of a work which represents the topic of the 
             content of the resource
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Publisher

Name:        Publisher
Identifier:  DC.Publisher
Definition:  An entity responsible for making the resource available
Required:    R
Repeatable:  Y
Comments:    N/A

Element: Date Issued

Name:        Date Issued 
Identifier:  DC.Date.Issued
Definition:  The date the digitized resource was made available
Required:    R
Repeatable:  N
Comments:    NLM is not permitting an unqualified date.  NLM is using the 
             W3C-DTF approved schema for form of date.

Element: Date Created

Name:        Date Created
Identifier:  DC.Date.Created
Definition:  Date of creation of the intellectual content of the 
             resource (if it differs from date issued)
Required:    O
Repeatable:  N
Comments:    N/A

Element: Date original form created

Name:        Date original form created
Identifier:  NLMDC.Date.Created.Original
Definition:  Date of creation of original format, if not originally 
             a digital object
Required:    O
Repeatable:  N
Comments:    N/A

Element: Date of last update

Name:        Date of last update
Identifier:  DC.Date.Modified
Definition:  Latest date of updating for minor changes or corrections
Required:    RA
Repeatable:  N
Comments:    N/A

Element: Major revision date

Name:        Major revision date
Identifier:  NLMDC.Date.Modified.Major
Definition:  Latest date of updating for major changes or new review of 
             the site
Required:    O
Repeatable:  N
Comments:    N/A

Element: Expiration date

Name:        Expiration date
Identifier:  NLMDC.Date.Expiration
Definition:  Date the resource is to be reviewed or pulled
Required:    RA
Repeatable:  N
Comments:    N/A

Element: Identifier, URI

Name:        Identifier, URI
Identifier:  DC.Identifier.URI
Definition:  A number or text string assigned by NLM which uniquely
             identifies the resource
Required:    O
Repeatable:  N
Comments:    NLM is not permitting an unqualified Identifier

Element: Identifier, URL

Name:        Identifier, URL
Identifier:  DC.Identifier.URL
Definition:  The URL of a resource
Required:    R
Repeatable:  Y
Comments:    N/A

Element: Identifier, NLM Bib UI

Name:        Identifier, NLM Bib UI
Identifier:  NLMDC.Identifier.BibUI
Definition:  NLM ILS catalog record ID number
Required:    O
Repeatable:  N
Comments:    N/A

Element: Identifier, ISSN

Name:        Identifier, ISSN
Identifier:  NLMDC.Identifier.ISSN
Definition:  International Serial Standard Number
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Identifier, ISBN

Name:        Identifier, ISBN
Identifier:  NLMDC.Identifier.ISBN
Definition:  International Standard Book Number
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Permanence Level¹

Name:        Permanence Level
Identifier:  NLM.Permanence.Level
Definition:  The extent to which a user can be assured that the 
             resource will remain stable and available
Required:    R
Repeatable:  N
Comments:    N/A

Element: Permanence Guarantor¹

Name:        Permanence Guarantor
Identifier:  NLM.Permanence.Guarantor
Definition:  The agency responsible for guaranteeing the availability
             and stability of the resource
Required:    R
Repeatable:  N
Comments:    N/A

Element: Language

Name:        Language
Identifier:  DC.Language
Definition:  Language of the resource 
Required:    R
Repeatable:  Y
Comments:    NLM is using the ISO 639.2 three letter codes.

Element: Type

Name:        Type
Identifier:  DC.Type
Definition:  Genre or class of material to which the resource belongs 
Required:    R
Repeatable:  Y
Comments:    Standard list based on resource types to be developed

Element: Rights

Name:        Rights
Identifier:  DC.Rights
Definition:  Rights held in and over a resource, such as intellectual
             property rights or copyright
Required:    R
Repeatable:  Y
Comments:    N/A

Element: Contributor

Name:        Contributor
Identifier:  DC.Contributor
Definition:  The name of the entity which contributed to creation of 
             the resource 
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Contributor, Role

Name:        Contributor, Role
Identifier:  NLMDC.Contributor.Role
Definition:  Designation of a function that describes the relationship
             between a Contributor and the resource
Required:    O
Repeatable:  Y
Comments:    The term "Role" is not actually used; rather a value from 
             a specified list is selected.

Element: Mandate

Name:        Mandate
Identifier:  NLM.Mandate
Definition:  If a specific legal instrument requires the resource to be 
             created or provided, supply the name of the specific act 
             or regulation 
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Notes

Name:        Notes
Identifier:  DC.Description.Notes
Definition:  Any general information about the resource 
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Table of Contents

Name:        Table of Contents
Identifier:  DC.Description.TableOfContents
Definition:  The contents of the resource 
Required:    O
Repeatable:  N
Comments:    N/A

Element: Edition

Name:        Edition
Identifier:  DC.Description.Edition
Definition:  Version or edition of the resource 
Required:    O
Repeatable:  N
Comments:    N/A

Element: Abstract

Name:        Abstract
Identifier:  DC.Description.Abstract
Definition:  A summary of the resource 
Required:    O
Repeatable:  N
Comments:    N/A

Element: Audience

Name:        Audience
Identifier:  DC.Description.Audience
Definition:  The population or level the resource is intended for 
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Geographic Coverage

Name:        Geographic Coverage
Identifier:  DC.Coverage.Spatial
Definition:  A geographic or spatial location covered by the 
             intellectual content of the resource 
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Temporal Coverage

Name:        Temporal Coverage
Identifier:  DC.Coverage.Temporal
Definition:  The time period or date range covered by the
             intellectual content of the resource 
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Relation

Name:        Relation
Identifier:  DC.Relation
Definition:  A reference to an unspecified type of related resource 
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Relation, Version of

Name:        Relation, Version of
Identifier:  DC.Relation.IsVersionOf
Definition:  Described resource is a version, edition, or adaptation 
             of the referenced resource.  Implies substantive changes
             to content, rather than difference in format 
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Relation, Is Format of

Name:        Relation, Is Format of
Identifier:  DC.Relation.IsFormatOf
Definition:  Described resource is the same intellectual content of
             the referenced resource, but presented in another format 
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Relation, Is Replaced By

Name:        Relation, Is Replaced By
Identifier:  DC.Relation.IsReplacedBy
Definition:  Described resource is supplanted or superceded by the 
             referenced resource 
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Relation, Replaces

Name:        Relation, Replaces
Identifier:  DC.Relation.Replaces
Definition:  Described resource supplants, displaces or supercedes the 
             referenced resource 
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Relation, Is Required By

Name:        Relation, Is Required By
Identifier:  DC.Relation.IsRequiredBy
Definition:  Described resource is required by the referenced resource, 
             either physicially or logically 
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Relation, Requires

Name:        Relation, Requires
Identifier:  DC.Relation.Requires
Definition:  Described resource requires the referenced resource to support 
             its function, delivery, or coherence of content 
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Relation, Is Part Of

Name:        Relation, Is Part Of
Identifier:  DC.Relation.IsPartOf
Definition:  The described resource is a physical or logical part 
             of the referenced resource 
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Relation, Has Part

Name:        Relation, Has Part
Identifier:  DC.Relation.HasPart
Definition:  The described resource includes the referenced resource 
             either physically or logically
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Relation, Is Referenced By

Name:        Relation, Is Referenced By
Identifier:  DC.Relation.IsReferencedBy
Definition:  The described resource is referenced, cited, or otherwise 
             pointed to by the referenced resource
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Relation, References

Name:        Relation, References
Identifier:  DC.Relation.References
Definition:  The described resource references, cites, or otherwise 
             points to the referenced resource
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Format

Name:        Format
Identifier:  DC.Format
Definition:  Information about the current physical or digital
             manifestation of the resource, such as software or 
             hardware needed, or duration or size of the resource 
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Contact Information, E-mail

Name:        Contact Information, E-mail
Identifier:  DC.Contact.Email
Definition:  An e-mail address for inquiries or further information 
             about the resource 
Required:    R
Repeatable:  Y
Comments:    N/A

Element: Contact Information, Section Affliliation

Name:        Contact Information, Section Affiliation
Identifier:  NLM.Contact.Affiliation
Definition:  The Section of the Library to which the resource belongs 
             or which is responsible for its maintenance
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Contact Information, Personal Name

Name:        Contact Information, Personal Name
Identifier:  NLM.Contact.PersonalName
Definition:  The name of a person to contact for inquiries or further 
             information about the resource
Required:    O
Repeatable:  Y
Comments:    N/A

Element: Change History

Name:        Change History
Identifier:  NLM.ChangeHistory
Definition:  Free text description of changes made to the resource 
             during the most recent update
Required:    O
Repeatable:  Y
Comments:    N/A

¹For further information about the NLM permanence ratings, see Developing Permanence Levels and the Archives for NLM's Permanent Web Documents.

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