HAO Scaffold: The Hallmarks of Aging Ontology Scaffold

The Hallmarks of Aging Ontology (HAO) scaffold — a proof-of-tractability ontology for the computable hallmarks of aging framework. The scaffold organizes 229 aging-related concepts across six semantic domains (hallmarks, molecular mechanisms, biomarkers, interventions, clinical phenotypes, age-related diseases), connected by 18 typed object properties in a three-level OWL 2 class hierarchy compliant with OBO Foundry conventions. This deposit includes the OWL ontology file, a standalone verification script, five SPARQL competency queries, and documentation.