Ontology Modeling Standards SKILL

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Most "how to model in OWL" advice is either a W3C spec (dense, correct, unreadable in a hurry) or a blog post (readable, and wrong about something important). This skill tries to be neither. It's a reference an AI coding assistant can load mid-task, checked line by line against the real specs: OWL 2, SKOS, SHACL, R2RML, Direct Mapping. Not against whatever the model half-remembers from training.

It covers two things most guides only do one of:

1. Modeling the ontology itself	Classes, properties, individuals, relationships, SKOS vocabularies, SHACL validation. Done properly, per spec.
2. Operationalizing it	Getting real data in and out: populating your ontology from an existing relational database (R2RML, OBDA), and going the other way, deriving and governing a relational schema from an ontology that already exists, so a bad schema change gets rejected before it lands.

That second part is the one nobody writes about, because there's no W3C standard for it. This skill says so up front instead of pretending one exists, and gives you the best practice available in its place.

The one thing to know before anything else

If you learn nothing else from this: **OWL doesn't validate data. SHACL does.**

	OWL restriction (e.g. owl:minCardinality 1)	SHACL shape (e.g. sh:minCount 1)
Purpose	Lets a reaso