P·C·D·M

The Portland Common Data Model (P·C·D·M) is a set of vocabularies published by Duraspace and used by certain institutions and communities in the library and cultural heritage sphere for modelling their collections. It comprises five parts :⁠—

• P·C·D·M Models builds on top of O·A·I Ore to provide basic structural modelling for Collections, their Objects, and the Files associated with them. This ontology only omits the term pcdm:AlternateOrder, whose meaning and utility is unclear.

• P·C·D·M Use provides subclasses for File which identify its intended use. The choice of modelling this using classes, rather than a relationship like has purpose, is a bit suspect, but a conversion from one to the other is not especially difficult.

• P·C·D·M Rights provides a few terms for specifying temporary, time‐limited overrides to rights statements. As this is use·case is fairly domain‐specific and niche, this ontology does not bother defining its terms.

• P·C·D·M Works expands P·C·D·M Models to add the concepts of Work and File Set. It also defines two classes for use with I·I·I·F, pcdmworks:Range and pcdmworks:TopRange, which are more suspect in utility and not included in this ontology.

• P·C·D·M File Formats provides a set of Concepts for denoting specific file format genres. These are a bit undocumented, and don¦t have a clear use·case, so they not been encoded into this ontology.