PCA Reference Data and Services

Pages under this heading describe how PCA ontologies in OWL 2 format can be accessed as files, by download or by direct retrieval in an editor.

## File formats

The following file formats are provided for ontologies.

• Turtle, an often preferred format for RDF (W3C, 2014)
• RDF/XML, RDF format supported in all tools, but less readable (W3C, 2014)
• JSON-LD 1.0, RDF in JSON, an evolving standard (W3C, 2014; see also version 1.1, 2020)
• Manchester Syntax, a readable OWL format (W3C Working Group Note, 2012)

While the files provided here will in general work well in popular tools, note that these formats evolve over time, and compatibility may vary.

On this website, axioms that apply to ontology entities are given in Manchester Syntax. For example, the webpage for the class Compressor displays a constraint hasFunction some ( realizedIn only Compression ), in Manchester Syntax.

## List of ontologies

The following ontologies are currently available. As the PLM-RDL is under active development, the list will be extended over time.

Both current and older versions of the ontologies will be available from this website.

Note that the collect ontology carries no RDL content of its own; it’s a hub that imports the other ontologies.

## Versioned folders

The column download link in the table above points to folders from which each ontologies may be downloaded. Each folder corresponds to an owl:versionIRI of the ontology, with file formats available. For example, here is the PLM process ontology folder for (pre-release) version 0.0.1:

File extensions correspond to formats as follows, with ontology process as an example:

file extension Format
plm-process.json json JSON-LD
plm-process.omn omn Manchester Syntax
plm-process.rdf rdf RDF/XML
plm-process.ttl ttl Turtle