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Comment by zozbot234 | Hacker News Reader

> In other words: if I wanted to build a private knowledge base, I don't want to pick or publish URIs and the fact that all the documentation pushes me towards open/sharing is just getting in the way.

RDF supports "blank nodes" for this use case. These are URI-less nodes that can only be referenced within the graph where they're defined. You'd use URI for reference to outside entities, which can be very relevant even in a private knowledge store.

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Blank nodes are one of the contested flame warzones of RDF.

The fact that they don't have a reified instance means that they are open to collapse with other blank nodes in certain inference scenarios and makes a lot of problems as hard as graph isomorphism.

Much better to go with plain old UUIDs instead.

RDF uses an open world assumption so "collapse" is always a possibility. That's why there are features like owl:DifferentFrom and related properties.

What you mean is the unique name assumption, which is distinct from the OWA, and may be viewed orthogonally and applied or not applied in different RDF contexts.

The problem with blank nodes is that they circumvent the UNA in every scenario, and you need something like "reified blank nodes" to resolve this, a.k.a. by using UUIDs treated as blank nodes.

See the following paper for a more in-depth discussion on the topic https://aidanhogan.com/docs/blank_nodes_jws.pdf

URIs a mostly namespaces, it has no bearing on being private data. If you know what your doing you’ll be using ontologies made by others, and like having a namespace for a library you’ll want the same for the terms/classes you use from them.

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