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This page describes the Identifier element for RegistryObject and not one of the Identifier child elements found in CitationMetadata or RelatedInfo.

Meaning & purpose

An identifier is a sequence of characters or words that uniquely identify an object within a particular context or the domain of a specified authority. It may be globally unique if the specified authority has a global domain.
Identifiers that are useful for discovery, linking of metadata records, reuse, or to support the functions of the metadata provider, can be recorded, even if they are not unique or persistent.

For detailed information on persistent identifiers, see the Guides on Persistent Identifiers (awareness, working and expert levels), Digital Object Identifiers, and handles (Handle minting service).

Identifier attributes

Identifier Type

An Identifier Type is required. Preferably, specify a type from the Identifier Type vocabulary below. For types not in the vocabulary, use the Namespace in as the Identifier Type.

To request the addition of Identifier Types not in the current vocabulary, please contact

Use in Research Data Australia

Identifiers are displayed within Research Data Australia as provided by the data provider, as clickable links (when possible), and prefixed with the identifier type.

Where two or more records (from the same or different data sources) share a common identifier, the records will be treated as describing the same thing. In Research Data Australia, these records are merged into a single search result and links to each of the merged records are displayed on the view page of each record. 

Best practice

For all records

  • Identifiers for collections, parties, activities or services being described, including non-unique and local identifiers, should be recorded in the Identifier element. The Identifier element can be repeated if multiple identifiers need to be described.
  • Contributors are strongly encouraged to provide a persistent, globally unique identifier such as a DOI , ORCID or PURL in the Identifier element. 

For collections

  • It is strongly recommended that all identifiers be persistent, i.e. a DOI or Handle , but any URI is acceptable.
  • If a global identifier is not available as a resolvable URL, provide it using a type that reflects the authority for the identifier. This will display as text only (not a resolvable link) in Research Data Australia.

For activities

  • Where a project is connected to a funding grant from the ARC or NHMRC, the project or program record should record the related grant identifier (PURL) in the Identifier element using the Identifier Type "arc" or "nhmrc" (rather than "purl"). This enables linking of project records to grant records supplied by funders. Where project descriptions from a research institution or agency use a local project identifier, these can also be provided.
  • As more funders supply grant information to Research Data Australia, persistent grant identifiers will be available for their grants as well. The list of funders contributing grant information can be viewed on the Explore Grants and Projects page in Research Data Australia.

For parties

  • If there is a globally unique identifier for a party, it is strongly recommended that it be provided in the Identifier element with the corresponding Identifier Type. This is preferably an ORCID, but may be an NLA Party Identifier, Scopus Author Identifier, or ResearcherID. Local username or staff IDs are also acceptable. System lookup facilities for ORCIDs and NLA Party Identifiers are available.
  • Include all relevant identifiers, as this helps in the disambiguation of similar names, discovery and record linking.

XML encoding examples

Identifiers for collections

<identifier type="doi"></identifier>
<identifier type="handle">hdl:102.100.100/15</identifier>
<identifier type="local">experiment/view/17</identifier>

Identifiers for parties

Persistent identifier examples:
<identifier type="orcid"></identifier>
<identifier type="AU-ANL:PEAU"></identifier>
<identifier type="researcherID"></identifier>
<identifier type="scopusID"></identifier>
Other resolvable identifier example:
<identifier type="uri"></identifier>
Local identifier examples:
<identifier type="local">researcher:3950184</identifier>
<identifier type="uri"></identifier>

Identifiers for activities

Australian Research Council identifier example:
<identifier type="arc"></identifier>

National Health and Medical Research Council identifier example:
<identifier type="nhmrc"></identifier>

Change history

Click here to view...
DateChange history
April 2010Consultation draft
26 Oct 2010Changed guidelines for use of National Library of Australia identifiers
14 Oct 2011Removed 'txt' suggested identifier type (previously included in error) — use 'local' instead of this type
14 Oct 2011Added link to best practice for activity identifiers, clarified types to use for party identifiers (ThomsonReuters, Scopus, VIAF, ORCID), added link to Contributing to Trove page
29 Nov 2011Added link to information about URL displays for identifiers
13 Mar 2013Added further information about ORCID identfiers
26 Nov 2013Added nhmrc as a new identifier type
27 Mar 2014Added information to Use in Research Data Australia section
20 Jan 2017Removed examples (ThomsonReuters, Scopus, VIAF) of using authority names for types instead of the suggested vocabulary, where no resolvable URI exits - no longer relevant
13 Jul 2017Page reviewed and updated
5 Apr 2018Updated examples to reflect the addition of new identifier types "researcherID" and "scopusID"
10 Jan 2018Clarified the use of identifier types "nhmrc" and "arc" for grants
05 Mar 2020Changed 'http" to 'https' for the DOI link in the examples
15 Jun 2022Add "ror" identifier type.
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