Table 6 Examples of undefined URIs

NeXtProt schema

http://www.w3.org/2002/07/owl#

http://www.w3.org/2002/07/owl (without hashtag) is defined.

hPSCreg vocabulary

http://www.w3.org/2000/01/rdf-schema#source

‘rdfs:source’ does not exist but ‘rdfs:Resource’ exists.

Resource Metadata Ontology

http://www.w3.org/ns/prov-o

It points to the RDF representation of PROV ontology, while the prefix of this ontology is http://www.w3.org/ns/prov#

http://www.w3.org/ns/prov-o-20130312

Version URI, resolving to the same content as above.

The WikiPathways Ontology

http://purl.org/dc/terms/accuralPeriodicity

Typo. It should be ’accrualPeriodicityMore’.

The UniProt ontology

http://www.w3.org/1999/02/22-rdf-syntax-ns

http://www.w3.org/1999/02/22-rdf-syntax-ns# (with hashtag) is defined.

Human Phenotype Ontology (HPO)

http://purl.org/dc/elements/1.1/license

Mix of DCMI namespaces. It should be ‘http://purl.org/dc/terms/license’.

Gene Ontology (GO)

https://doi.org/10.1186/s13326-017-0126-0

Every Digital Object Identifier (DOI) is not ’defined’ in a machine-readable way.