Currently, the Solid Protocol and its specifications lack the necessary vocabulary and processes for ensuring transparency and accountability in the use of data. In particular, to deal with the obligations and requirements required by regulations related to (personal) data protection and privacy. In addition, the lack of a guiding vocabulary leads to no common mechanism through which apps can request data and how Solid maintains information about its use. To address these, we propose PLASMA – a policy language to describe the entities, infrastructure, legal roles, policies, notices, and records to understand and establish responsibilities and accountability within the Solid ecosystem. We present how ontology design patterns using PLASMA can provide a common interface to create structured policies, records, and logs within the diverse Solid use cases, and thereby solve challenges regarding the management and governance of apps and their privacy considerations.

This work was funded partially by the project Knowledge Spaces: Técnicas y herramientas para la gestión de grafos de conocimientos para dar soporte a espacios de datos (Grant PID2020-118274RB-I00, funded by MCIN/AEI/ 10.13039/501100011033). This research has also been supported by the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 813497 (PROTECT) and by the ADAPT SFI Research Centre funded by Science Foundation Ireland and co- funded under the European Regional Development Fund (ERDF) through Grant#13/RC/2106_P2.