Packaging Data using RO-Crate: Glossary

RO-Crate provides a structure to make FAIR data packages

schema.org in JSON-LD provides a controlled vocabulary for FAIR metadata

Each entity of the crate is described separately

Cross-references between entities create a graph

The RO-Crate specification recommends which types and keys to use

Adding a RO-Crate Metadata file to a folder turns it into an RO-Crate

The RO-Crate Root is the top-level folder of the crate

RO-Crate uses schema.org as base vocabulary

The JSON-LD context enables optional Linked Data processing

Descriptions are listed flatly as entities in the @graph array

The RO-Crate Metadata Descriptor describes the JSON-LD file itself

RO-Crate specifications are versioned

The version of RO-Crate is indicated using the conformsTo property

The RO-Crate Root is the top-level object of the RO-Crate

The root identifier may be a URL, but commonly just ./ for the current folder

Name, description, date published and license are required for the RO-Crate Root

RO-Crate allows multiple licenses for different parts

The @id uniquely identifies the entity within the RO-Crate

The @id key is used for cross-referencing

Multiple types can be listed by using an array

Data entities are files & folders within the root, as well as external Web references

Required properties for files are name and encodingFormat

License can be overridden for particular data entities

Contextual entities are not considered part of the crate

Cross-references should be expanded as contextual entities

It is recommended to provide a human-readable name for licenses

Authors are described as separate entities

Organization entities can be shared by multiple persons having the same affiliation

Crate authors made (some) of the crate’s content

Publishers of an RO-Crate are typically organizations

RO-Crate metadata files are valid JSON-LD

The JSON-LD Playground can do basic validation and visualization

Further use of RO-Crate as Linked Data is possible, but may require handling of relative URI references

The JSON-LD @context maps JSON keys to schema.org vocabulary

A @base URI is needed to make absolute URIs

arcp and UUID can be used for RO-Crates that are not exposed on the Web

RO-Crate can be rendered into a HTML preview

RO-Crate previews tend to show each entity separately

The preview HTML can be added as part of the RO-Crate

A single RO-Crate lists all the entities

The order of entities in the @graph array is not important

RO-Crate specification has further details, e.g. additional contextual entities