The Dulcinea directory indexes active Spanish academic journals. It currently lists 1905journals, of which 1,293 are free for authors (no APCs) and readers and use open licences. Of these, 1,055 belong to universities and research-performing organisations (RPOs) , and 238 to scholarly societies. The aim of this study was to identify and analyse the characteristics of these journals in accordance with the criteria defined by the Diamond Discovery Hub (DDH): 1. Persistent identification.2. Scholarly journal. 3. Open Access with open licences. 4. No fees. 5. Open to all authors. 6. Community-owned. Eighty-one percent of these journals are owned and published by universities and research centres. The distribution by discipline is as follows: fine and performing arts 1.9%, health sciences 7.0%, life sciences 3.4%, experimental sciences 1.8%, social sciences 49.0%, humanities 34.0%, engineering 1.9%, mathematics and physical sciences 1.2%. With regard to disciplines, journals in the social sciences and humanities account for the highest percentages of journals published by universities and research centres, whilst in the health sciences the highest percentage corresponds to associations or learned societies. The following table shows the type of license used by journals from institutions and association/learned societies.

With regard to Creative Commons licences, CC BY-NC-ND is the most widely used by societies (40,63.3%), whilst in the case of academic institutions, the use of CC BY (34.57%) and CC BY-NC-ND (34.59%) is most common.

Copyright belongs mainly to publishers and, in 58,6% of cases, to authors (18.4% exclusively and 26,2% keep copyright and grant a publisher the right to publish the work through a non-exclusive licensing agreement)). In summary, the Spanish journals analysed meet all the criteria for diamond open access journals, although not all demonstrate the same degree of openness due to the licences used; in this case, the CC BY-NC-ND licence, which is the most restrictive of the Creative Commons licences, means that their openness is not uniform.