What is the CTDL?

The Credential Transparency Description Language (CTDL) is the family of de facto standards for making descriptions of credentials and other resources available as data for search and discovery and cross-system interoperability.  You can think of the CTDL as a large dictionary of terms that is at your fingertips for creating descriptions where you can use all of the terms or only those terms that meet your needs.  

The power of the CTDL comes from every term having semantic meaning and from using a model based on specifications for the semantic web.  This means that the CTDL is designed to include terms for linking data.  The CTDL linked data structure enables telling complete stories to answer questions such as how much a credential cost, how long to earn it, requirements to enroll, courses that are required, transfer value, preparation for other credentials, jobs it prepares people for, pathway options, outcomes, and more. 

There’s three CTDL schemas available for anyone to use:


Large schema for all types of credentials and a wide range of adjacent resources such as learning opportunities, assessments, pathways, transfer value, and more. 

CTDL Achievement Standards Network (ASN)

The schema for descriptions of competencies. Competency is broadly defined to include assertions of academic, professional, occupational, vocational and life goals, outcomes, and standards, however labeled such as knowledge, skills and abilities, capabilities, dispositions, habits of mind, or habits of practice. 

Quantitative Data (QData)

The schema for numeric and statistical data such as aggregated completion rates or employment and earnings. 

This is a broad overview of the CTDL. To review the family of standards, all CTDL schemas, mapping, guidance, serialization, and more visit our technical site where you can also review the CTDL Handbook.

How Credential Engine’s Publishing Tools Use the CTDL

All of Credential Engine’s publishing tools output data as CTDL linked data whether for systems providing open data (LOD) or closed systems with data behind  firewalls.  CTDL is fundamental to all data published to the Credential Registry as Linked Open Data.  Whether using the bulk upload or API options, information is converted to CTDL linked data structure. The Credential Finder, a tool for seeing all of the data published to the Credential Registry uses CTDL for all search filters, search results, and detail pages.  

Credential Finder

See published credentials in action. Credential Finder was developed by our team to show published data. Through Credential Finder, you can find credentials, compare them, and explore additional information.

Credential Registry Guidance Site 

The Credential Registry Guidance is the source of knowledge for guidance, support, and instructions for all Credential Engine’s products, including CTDL, Credential Publisher, Credential Finder, and more.

Get Started with CTDL

View your Publishing Options

Review your publishing options on our Credential Registry Guidance Site.

Start Publishing

Start publishing your organization’s credentials and other related information as CTDL Linked Open Data to the Credential Registry.

CTDL Handbook

Our Credential Engine Schemas Handbook contains basics and advanced details about using all three CTDL schemas.

Tailored Services

We offer customized services for your stakeholders’ needs. Whether you need assistance developing tools for your users, publishing credentials, or need help managing your credential transparency initiatives, we can help.

Get in Touch

Our team of experts is ready to help you embark your credential transparency journey. Whether you have questions about our technologies, services, or don’t know how to get started, we’re here to assist.

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