DOI System Metadata
What every DOI held here carries: the elements of the DOI System Metadata, and the basic metadata each kind of work needs.
Checked now: 928 of 928 records held here carry every System Metadata element and the basic metadata their sub-type needs. Every Kernel Metadata Declaration was last checked against the DOI Foundation's own schema on 01 Oct 2026: 928 of 928 valid.
Files: this document (Markdown) · the specification (JSON) · the metadata format · the rules · the policies · the quality procedure
Basic metadata per referent sub-type
Required: a record without it is not complete. Recommended: the record is complete without it, and the record page lists what is absent. The same table drives the check.
| Sub-type | Required | Recommended | Crossref requires |
|---|---|---|---|
Journal articleJournalArticle | the publication date (at least the year) · the journal it belongs to — its title and its ISSN (or the journal's own DOI) | its author(s), editor(s) or corporate author · the volume number · the issue number · the first page or an article number · the language of the content · an abstract or description · the licence · the reference list | article: titles, publication_date (year), doi_data; journal: full_title, ISSN or title-level DOI |
Journal (title-level DOI)Journal | the publisher | its own ISSN · the language of the content | journal: full_title, ISSN or title-level DOI and URL |
Journal issueJournalIssue | the journal it belongs to — its title and its ISSN (or the journal's own DOI) · the publication date (at least the year) · its issue or volume number | the volume number · the issue number · the language of the content | issue: issue, publication_date (year) |
Journal volumeJournalVolume | the journal it belongs to — its title and its ISSN (or the journal's own DOI) · the publication date (at least the year) · the volume number | the language of the content | journal_volume with the journal's full_title and ISSN |
BookBook | the publication date (at least the year) · the publisher | an ISBN (its own or its book's) · its author(s), editor(s) or corporate author · the language of the content · the licence | book: titles, publication_date (year), publisher |
Book chapterBookChapter | the book it belongs to — its title · the publication date (at least the year) | its author(s), editor(s) or corporate author · the first page or an article number · an ISBN (its own or its book's) | chapter: doi_data (titles, contributors, pages, publication_date recommended), inside its book |
Book seriesBookSeries | its own ISSN · the publisher | the language of the content | series: titles, ISSN, volume, publication_date (year), publisher |
Conference paperConferenceProceedings | the proceedings it belongs to — their title · the publication date (at least the year) · its author(s), editor(s) or corporate author | the first page or an article number · an abstract or description · the licence · the reference list | conference paper: contributors, titles, doi_data; proceedings: proceedings_title, publisher, publication_date (year) |
Conference proceedings (the volume)ConferenceProceedings/volume | the publication date (at least the year) · the publisher | an ISBN (its own or its book's) · its author(s), editor(s) or corporate author | proceedings: proceedings_title, publisher, publication_date (year) |
Dataset or databaseDataset | the publication date (at least the year) · the publisher | its author(s), editor(s) or corporate author · an abstract or description · the licence | database: titles; dataset: doi_data (DataCite requires creator, title, publisher, publication year, resource type) |
ReportReport | the publication date (at least the year) | its author(s), editor(s) or corporate author · the publisher · the language of the content | report: title, publication_date (year) |
Thesis or dissertationThesis | the publication date (at least the year) · the institution that issued or awarded it (the publisher or corporate author, an organisation) | its author(s), editor(s) or corporate author · the language of the content | dissertation: titles, approval_date, institution, doi_data |
StandardStandard | the publication date (at least the year) · the publisher · the standard's designation (an identifier besides the DOI) | the language of the content | standard: title, designator, approval_date, standard_body_name, standard_body_acronym |
Figure, table or supplementary fileFigure | the work it is part of, by that work's DOI | the publication date (at least the year) | component: doi_data, under its parent work |
Web resource or posted contentWebResource | the publication date (at least the year) | its author(s), editor(s) or corporate author · the publisher · an abstract or description | posted content: titles, posted_date, doi_data |
1 October 2026. Every DOI this registry holds is described by the DOI System Metadata: the elements of the DOI Handbook's System Metadata Model (section 10.1), which are the system metadata of ISO 26324:2025 (Annex B), plus the basic metadata its kind of work needs. This document is the registry's declaration of that model: where each element comes from in a record, what each referent sub-type must carry, and how every record is checked. On 1 October 2026 the registry held 928 records, all of Journal of Science and Technology (JST), every one first registered at Crossref.
1. The elements, and where each comes from
ISO 26324 asks that "metadata describing and identifying the referent to which the DOI name is being assigned shall be recorded promptly and accurately", and that it meet "the minimum requirements of System Metadata including Basic Metadata for the relevant sub-type of referent" (DOI Handbook 4.2.3). The Handbook's model names seven descriptive and two administrative elements; Annex B of the standard names the same set. The example is 10.46243/jst.2025.v10.i12.pp35-41.
| DOI Handbook 10.1 | Occurs | ISO 26324:2025, Annex B | In the record (smartscholars-doi-metadata/1.0) | In the Kernel Metadata Declaration | The example |
|---|---|---|---|---|---|
| DOI name | 1 | DOI Name | doi | referentDoiName | 10.46243/jst.2025.v10.i12.pp35-41 |
| alternateIdentifier | 0-n | Referent Identifier(s) | identifiers other than the DOI; relations with role IsSameAs | referentCreation/identifier | none besides the DOI |
| referentName | 1-n | Referent Name(s) | titles | referentCreation/name | Three-Dimensional (3D) Food Printing: Technology, Applications, and Ethical Considerations (PrincipalTitle, en) |
| referentType | 1 | Referent Type | referent | primaryReferentType | Creation |
| referentSubType | 1 | Referent Sub-Type | type (a creationType of the value sets) | referentCreation/type | JournalArticle |
| relatedIdentifiers | 0-n | — | container or relations, only for a component whose description is its parent's | linkedCreation | none needed |
| basicMetadata | 1 | Basic Metadata | the fields its sub-type needs (section 3) | principalAgent, linkedCreation (Part, with volume, issue and page), creationDate, languageOfReferentContent, structuralType, mode, character | Manasa Mandapati (Author, ORCID 0009-0003-2056-724X); Longman Publishers; 2025-12-15; Journal of Science & Technology, ISSN 2456-5660, vol. 10, no. 12, first page 35; en |
| registrationAuthorityCode | 1 | Registration Authority | record.source_agency | — (see below) | Crossref |
| issueDate | 1 | Created Date | record.registered | — (see below) | 2025-12-26 |
The administrative elements describe the DOI name; the Kernel declaration's look alike but describe the declaration. registrationAuthorityCode is the agency "that issued this DOI name" and issueDate the "date when this DOI name was issued" (Handbook 10.1). For every DOI held today that is Crossref, and the date Crossref first registered it — doi.org's own lookup agrees (doi.org/doiRA answers "Crossref" for a JST DOI). A DOI issued by Crossref stays Crossref's in its system metadata whatever this registry becomes. In the Kernel Metadata Declaration, registrationAgencyDoiName is "the DOI name of the Registration Agency responsible for issuing this Declaration" and issueDate "the date on which this Declaration was issued" (doi:10.1000/276). Until Smart Scholars is appointed, our declarations carry the marker 10.0/smart-scholars-draft there, which no Registration Agency can hold, and say in the XML that they are drafts.
A name, not a placeholder. Crossref holds no title for JST's eight issue DOIs, and the record then carried the marker "(no title on the Crossref record)". That is no name a reader knows the work by, so it never counts as a referentName. An issue or a volume without a title is named from its own record: "Journal of Science and Technology, vol. 10, no. 08 (2025)" for 10.46243/jst.2025. Every part comes from the same Crossref record. Any other record still carrying the marker is shown as not complete.
Languages are written as the DOI Schema types them (xs:language, BCP 47: en); the ISO 639-2 equivalent of en is eng.
2. The referent sub-types registered here
Every record is a Creation. Its sub-type is one of fourteen creationType values of the DOI Schema's Attribute Value Sets 2.3 (doi:10.1000/282), so a value we write is a value the model accepts: JournalArticle, Journal, JournalIssue, JournalVolume, Book, BookChapter, BookSeries, ConferenceProceedings (a paper, or the proceedings volume), Dataset, Report, Thesis, Standard, Figure, WebResource. The format specification lists which Crossref types each is read from.
3. Basic metadata per referent sub-type
"Basic metadata (if needed) is specified by each registration agency for its referent subtypes", and the definitions "shall be placed in a repository" (DOI Handbook 4.2.3). This is that specification. Required follows what Crossref requires for the same kind of record (Crossref, required and recommended elements), so a record Crossref accepts is one this registry accepts. Recommended adds what Crossref recommends and what DataCite makes mandatory: creator, title, publisher, publication year and resource type (DataCite Metadata Schema 4.7). A record without a recommended item is still complete; its record page lists what is absent. The registry's page shows the same table, made from the code that runs the check.
| Sub-type | Required | Recommended | What Crossref requires for it |
|---|---|---|---|
Journal article JournalArticle | the publication date (at least the year) · the journal it belongs to — its title and its ISSN (or the journal's own DOI) | its author(s), editor(s) or corporate author · the volume number · the issue number · the first page or an article number · the language of the content · an abstract or description · the licence · the reference list | article: titles, publication_date (year), doi_data; journal: full_title, ISSN or title-level DOI |
Journal (title-level DOI) Journal | the publisher | its own ISSN · the language of the content | journal: full_title, ISSN or title-level DOI and URL |
Journal issue JournalIssue | the journal it belongs to — its title and its ISSN (or the journal's own DOI) · the publication date (at least the year) · its issue or volume number | the volume number · the issue number · the language of the content | issue: issue, publication_date (year) |
Journal volume JournalVolume | the journal it belongs to — its title and its ISSN (or the journal's own DOI) · the publication date (at least the year) · the volume number | the language of the content | journal_volume with the journal's full_title and ISSN |
Book Book | the publication date (at least the year) · the publisher | an ISBN (its own or its book's) · its author(s), editor(s) or corporate author · the language of the content · the licence | book: titles, publication_date (year), publisher |
Book chapter BookChapter | the book it belongs to — its title · the publication date (at least the year) | its author(s), editor(s) or corporate author · the first page or an article number · an ISBN (its own or its book's) | chapter: doi_data (titles, contributors, pages, publication_date recommended), inside its book |
Book series BookSeries | its own ISSN · the publisher | the language of the content | series: titles, ISSN, volume, publication_date (year), publisher |
Conference paper ConferenceProceedings | the proceedings it belongs to — their title · the publication date (at least the year) · its author(s), editor(s) or corporate author | the first page or an article number · an abstract or description · the licence · the reference list | conference paper: contributors, titles, doi_data; proceedings: proceedings_title, publisher, publication_date (year) |
Conference proceedings (the volume) ConferenceProceedings/volume | the publication date (at least the year) · the publisher | an ISBN (its own or its book's) · its author(s), editor(s) or corporate author | proceedings: proceedings_title, publisher, publication_date (year) |
Dataset or database Dataset | the publication date (at least the year) · the publisher | its author(s), editor(s) or corporate author · an abstract or description · the licence | database: titles; dataset: doi_data (DataCite requires creator, title, publisher, publication year, resource type) |
Report Report | the publication date (at least the year) | its author(s), editor(s) or corporate author · the publisher · the language of the content | report: title, publication_date (year) |
Thesis or dissertation Thesis | the publication date (at least the year) · the institution that issued or awarded it (the publisher or corporate author, an organisation) | its author(s), editor(s) or corporate author · the language of the content | dissertation: titles, approval_date, institution, doi_data |
Standard Standard | the publication date (at least the year) · the publisher · the standard's designation (an identifier besides the DOI) | the language of the content | standard: title, designator, approval_date, standard_body_name, standard_body_acronym |
Figure, table or supplementary file Figure | the work it is part of, by that work's DOI | the publication date (at least the year) | component: doi_data, under its parent work |
Web resource or posted content WebResource | the publication date (at least the year) | its author(s), editor(s) or corporate author · the publisher · an abstract or description | posted content: titles, posted_date, doi_data |
Every sub-type also needs the elements of section 1 that are always required: the DOI name, at least one referentName, the referentType, the referentSubType, and the date the DOI name was issued.
4. How each record is checked
- On registration and on every change, the record must meet the metadata format (the Smart Scholars DOI Metadata Format 1.0). A record that fails is refused, with every reason in words, and nothing is written.
- The System Metadata check runs on every record held. Each record page shows the elements by both names and says "complete" or lists what is missing. The registry's administrator sees the count of every record; the page of this document shows the same count, checked when the page opens.
- From a date the registry sets, a new name must be complete. Until that date, an incomplete record is registered and shown as not complete. The policies (version 1.1, section 2) set 1 January 2027, with 90 days' notice. A DOI read in from Crossref or the Handle System is never refused for it: its registration is a fact being recorded, and the record page shows what it lacks.
- Against the DOI Foundation's own schema. The registry keeps the Foundation's files unchanged: DOIMetadataKernel.xsd (doi:10.1000/276), DOIAVS.xsd 2.3 (doi:10.1000/282) and iso3166a2.xsd, with their SHA-256 hashes. Whenever the registry's administrator asks, every record's Kernel Metadata Declaration is validated against them; the date and the count are kept and shown on this page. Before every release of the registry's software, the declarations of sample records of each kind held today — a journal article, a journal issue, a journal and a Crossmark policy page — are validated against them too.
On 1 October 2026, before the change that names untitled issues, 920 of the 928 records were complete. The eight JST issue records carried the no-title marker. They are complete once the prefix is read in from Crossref again, because that reading names each issue from its own record.
5. What the registry publishes
- For each DOI: the record page (its "System metadata" card); the System Metadata Declaration as JSON (
resolve.php?doi=…&as=system), whose element names and order follow the Handbook's model; the Kernel Metadata Declaration as XML (&as=xml). - The specification: this document (
system-metadata.php, Markdown at?file=md) and its table as JSON (system-metadata.php?as=json). - In bulk: the JSON Lines dump carries every record, and each row links to its System Metadata Declaration.
6. Requests to the Metadata Working Group
None is needed today: every value written is in the Attribute Value Sets 2.3. One may follow. A ROR identifier for an organisation travels as a ProprietaryIdentifier whose address says it is ROR, because ROR is not a partyIdentifierType in the value sets. Registration Agencies "can request … the addition of new values to open lists" (DOI Handbook 4.3.4).
Sources
- The DOI Handbook, HTML edition: 4.2 (metadata requirements according to ISO 26324), 4.3 (the System Metadata model, its policies, additional metadata, extension) and 10.1 (the System Metadata model, descriptive and administrative elements) — doi.org/doi-handbook/html, read 1 October 2026; the same in the DOI Handbook 2025 (PDF).
- The DOI Schema, doi:10.1000/276 — DOIMetadataKernel.xsd; the Attribute Value Sets 2.3, doi:10.1000/282 — DOIAVS.xsd.
- ISO 26324:2025, Information and documentation — Digital object identifier system, Annex B (Smart Scholars' licensed copy; not reproduced here).
- Crossref: required, recommended and optional elements, read 1 October 2026.
- DataCite Metadata Schema 4.7, properties overview, read 1 October 2026.
- doi.org's RA lookup.
