The DIAMAS project has developed a comprehensive set of resources and guidelines to support the quality and sustainability of Diamond Open Access (OA) publishing. It includes a variety of resources specifically tailored to meet the needs of Diamond OA publishers, journal editors, and service providers. This presentation will highlight the key components of the knowledge base, with a special focus on the training platform.

At the core of the resources is the Diamond Open Access Standard (DOAS), a quality framework that sets out required and desired criteria across seven key components of scholarly publishing: (1) Funding; (2) Legal ownership, mission and governance; (3) Open Science; (4) Editorial management, editorial quality, and research integrity; (5) Technical service efficiency; (6) Visibility, communication, marketing, and impact; and (7) Equity, Diversity, Inclusion and Belonging (EDIB), multilingualism, and gender equity (Consortium of the DIAMAS project, 2024).

To aid the implementation of this core framework, DIAMAS has created:

• Toolsuite (https://toolsuite.diamas.org): A series of short, high-level articles introducing the core components of DOAS, complemented by glossaries, keywords, and frequently asked questions (FAQs). All materials are available in English, Spanish, Croatian and Portuguese (Armengou, Alevizos, et al., 2024).
• Guidelines (https://toolsuite.diamas.org/guidelines): A collection of 18 articles providing practical advice for aligning publishing practices with DOAS criteria. The high-level topics of DOAS are broken down into subtopics that highlight areas where practical guidance is most needed. For example, Open Science is addressed through articles such as Use of open licenses in open access publishing, Self-archiving policy, Availability of research protocols, methods and software, Handling negative research results, Preprints, and Research data sharing policy. Guidelines are available in English, Spanish, Croatian and Portuguese (Armengou, Bowker, et al., 2024).

Recognising complexity in certain areas, additional materials have been developed:

• Financial sustainability resources (https://toolsuite.diamas.org/toolsuite-sustainability): A comprehensive set of resources providing both strategic insights and practical guidance to support the sustainability of Diamond OA publishing. The materials focus on funding models, workforce sustainability, advocacy and collaborative practices, and include guides, templates, case studies and research (Hughes 2025).
• Equity, Diversity, Inclusion and Belonging (EDIB) Getting Started Guide, which outlines the core elements of EDIB and offers foundational tools to help editors and publishers create a strategy tailored to their specific context (Bowker, Laakso and Pölönen, 2025).

These resources served as a starting point for developing interactive training materials that address skill gaps identified during the project. The modular training programme, to be released in late May 2025, comprises 13 courses hosted on a dedicated Moodle platform

within the European Diamond Capacity Hub. Designed for self-paced learning, it employs diverse formats including presentations, infographics and checklists, and incorporates interactive elements such as quizzes, self-reflection exercises and flip cards. Training materials can be used as standalone resources or integrated into institutional training efforts. They are released under an open licence and designed for easy localisation and reuse. The primary audience for the training programme includes journal editors and Diamond OA publishers. Still, the materials can be helpful to trainers, institutional leaders, policymakers, funders, and researchers involved in scholarly communication.

The DIAMAS knowledge base reflects the values of the Diamond OA community: collaboration, openness and a commitment to equitable scholarly communication. By providing standards, tools and training materials, the DIAMAS project supports publishers and service providers in enhancing quality and building more sustainable publishing practices.