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CoreTrustSeal

CoreTrustSeal is the entry-level, community-run certification for trustworthy digital repositories. It emerged in 2017 from the merger of two previously separate schemes, the Data Seal of Approval (DSA) and the ICSU World Data System (WDS) certification, which combined their requirements into a single set rather than continuing to run parallel, only partly compatible certifications. It is distinguished from higher-tier schemes by scope and depth of assessment rather than by subject coverage.

ByCASRAI Editorial Board
· Last updated 5 Sept 2026
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Editorial commentary

CoreTrustSeal is the entry-level, community-run certification for trustworthy digital repositories. It emerged in 2017 from the merger of two previously separate schemes: the Data Seal of Approval (DSA) and the ICSU World Data System (WDS) certification. Rather than two organisations continuing to run parallel, only partly compatible certifications, DSA and WDS combined their requirements into one shared framework, governed by the CoreTrustSeal Standards and Certification Board, so repositories certify once against one recognised standard instead of choosing between two. See WDS certification for how the World Data System’s own certification role changed after the merger.

The 16 requirements

Repositories self-assess against 16 numbered requirements (plus a non-scored background item) grouped into three areas: organisational infrastructure (mission and scope, rights management, continuity of service, legal and ethical compliance, governance and resources, expertise and guidance), digital object management (provenance and authenticity, deposit and appraisal, preservation planning, quality assurance, workflows, discovery and identification, reuse), and technology (storage and integrity, technical infrastructure, security).

Process, fee, and renewal

Applicants register, submit a self-assessment (within three months), and go through peer review by two reviewers from other certified repositories (~2 months), Board assessment (~2 weeks), and up to five revision cycles, with a final decision within about a month of a successful review; the whole process is capped at two years from submission. The fee is EUR 3,000 (as of February 2024), with bulk/peer-review discounts and waivers for low- and middle-income-country repositories. Certification runs three years and is renewable.

Position among repository-trust frameworks

CoreTrustSeal is the ‘Core’ level in the broader trust-framework landscape that also includes the nestor Seal and formal ISO 16363 assessment — see trusted digital repository for how those tiers relate. CoreTrustSeal is recognised by major funders, the European Commission, and programmes such as OpenAIRE and EOSC as evidence a repository meets baseline trustworthiness expectations; the UK Data Service is one certified example.

References

Also known as

CTS

Machine-readable encodings

Use in your systems

JATS XML <role> element
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Schema.org DefinedTerm (JSON-LD)
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Referenced across the research world

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