The concept of Data Management Plan (DMP) has emerged as a fundamental tool to help researchers through the systematical management of data. The Research Data Alliance DMP Common Standard (DCS) working group developed a core set of universal concepts characterising a DMP in the pursuit of producing a DMP as a machine-actionable information artefact, i.e.,machine-actionable Data Management Plan (maDMP). The technology-agnostic approach of the current maDMP specification: (i) does not explicitly link to related data models or ontologies, (ii) has no standardised way to describe controlled vocabularies, and (iii) is extensible, but has no clear mechanism to distinguish between the core specification and its extensions. Currently, the maDMP specification provides a JSON serialisation and schema to operationalise the approach. Such approach, however, does not address the concerns above. This paper reports on the community effort to create the DMP Common Standard Ontology (DCSO) as a serialisation of the DCS core concepts, with a particular focus on a detailed description of the components of the ontology. Our initial result shows that the proposed DCSO can become a suitable candidate for a reference serialisation of the DMP Common Standard.