Biomedical ontology matching is a key step for semantic interoperability in medical AI systems, supporting clinical terminology mapping, cross-resource search, biomedical knowledge graph construction, and phenotype-aware data integration. This paper presents ARB, an auditable symbolic candidate-generation module designed for settings where external biomedical resources, learned embeddings, or reference-alignment calibration are unavailable or undesirable. ARB starts from a token inverted-index blocker, rescues missed candidates through hierarchy-pooled and neighbour-label evidence under a purity gate, and applies same-source structural dominance pruning to reduce lexically similar false siblings. The module is evaluated on seven OAEI 2013 biomedical ontology-matching tasks using candidate-pool metrics and a fixed downstream Hungarian matcher, and on five Bio-ML 2024 localranking tasks as a matcher-independent scoring check. Across the OAEI tasks, the rescue mechanism improves candidate recall by 2.0–10.8 percentage points while limiting gated pool growth to 5–24%. On Anatomy, structural dominance pruning alone raises downstream F1 from 0.197 to 0.366 under the fixed matcher, whereas the full ARB configuration (rescue plus pruning) reaches 0.375. Pruning is less reliable on structurally heterogeneous SNOMED-related tasks. On Bio-ML 2024, ARB achieves a meanMRRof 0.813 and mean Hits@1 of 0.760 using only ontologyinternal symbolic evidence. The module is most useful when lexical blocking leaves meaningful recall headroom; recall-saturated phenotype tasks instead require conservative rescue. These results support ARB as an auditable candidate-generation and cleaning component for biomedical knowledge integration, rather than as a complete ontology matcher or a final clinical mapping tool.



