072

blvh:slot:072

sampling_operation; slot=072; candidate_set=ambiguity; subgroup=boundary_geometry; target_period=prefer 1800-1899; diversify decades; query_pool=; mask_rule=prefer unusual rectangularity/dense crop/text-caption-image boundary ambiguity; book_cap=max 2 selected images per book; selection_method=crop_masks structural filter + human diversity review; required_provenance=fname, record_id, all instances, bbox, score, area, rectangularity, model_id, model_sha; status=TO_SELECT; sampling_version=blvh-0.2. observation_status=machine_selection_plan; NEVER promote the semantic query to a factual subject label.