Are (RDF) vocabularies/ontologies on-topic?

Question

(As the What topics can I ask about here? help page doesn’t list what is on-topic here, and the answers I found on Meta are rather broad, I’m not sure if, or to which extent, questions of the following kind are welcome here.)

Would it be on-topic to ask for an RDF vocabulary/ontology?

(While there are linked-data and rdf tags, there doesn’t seem to be a question like that yet.)

Examples:

• "Is there a vocabulary for data about fictional persons?" (where the OP lists what properties/classes they might need)
  An answer could suggest FOAF, Schema.org’s Person, etc.

• "How could I annotate my weather data?" (where the OP describes/shows their Open Data and looks for suitable RDF vocabularies to annotate it)

• "Is there an ontology that models xy?" (where the OP is not looking only for a vocabulary of properties/classes, but also defined OWL constraints)

• "Vocabulary that defines URIs for each character from Studio Ghibli works?" (here the OP is not looking for properties to annotate their data about the characters, but simply for URIs they could use to unambiguously identify the characters, e.g. for owl:sameAs; so here the corresponding data about the characters is not necessarily required to be open itself, as the OP is not interested in the data, only the URIs)

I’m not sure how to interpret open in these case.

Is a vocabulary Open Data when its documentation is openly licensed, or when its publicly available, or simply when the authors allow others to use their vocabulary URIs (even if the vocabulary documentation/RDF itself is not openly licensed) (but would it even be possible for bare URIs to be non-open)?
Or would it be a side-question (similar to questions about tools), i.e., looking for vocabularies (if open or not?) to annotate your own Open Data?

The typical use case only requires to a) access the documentation/RDF (but not to republish/reuse it) and b) to re-use the URIs defined in this documentation/RDF.

Answer 1

It make sense to ask those questions on the open data stack exchange. Correct me if I am wrong but RDF is just a data sharing format.

If the question is regarding open license (how to release or data request) request for vocabulary and ontology topics are welcome here.

Answer 2

Would it be on-topic to ask for an RDF vocabulary/ontology?

I think yes, since many people consider the presense of these vocabularies or ontologies as an essential data quality characteristic or even as an next step in the 5-star data model:

• in theory
• in practice.

Surely, without these vocabularies or ontologies, RDF data is just another kind of data silo.

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I’m not sure how to interpret open in these case. 〈…〉 would it even be possible for bare URIs to be non-open?

You are right, in Linked Enterprise Data, as opposed to Linked Open Data, these URIs sometimes are just unknown to outsiders or at least non-dereferenceable for them. ISO 15926 RDLs are an example.