Use only the attached synthetic input. Return a JSON object with these exact fields: unique_current_tags, removed_tags, duplicate_tag, line_destination. Use null for information not stated. Preserve identifiers, units and revision states. Lists follow first appearance in the input, except an explicitly requested chronological order. Use snake_case for categorical labels. Do not add inferred engineering decisions.
Field types: {"unique_current_tags": "array of strings", "removed_tags": "array of strings", "duplicate_tag": "string", "line_destination": "null when unstated"}

Task: Separate tag recognition from connectivity interpretation. Reconcile extracted tags against a reviewed register before attempting drawing-level relationships.
Preserve PT-101 and P-101 as different tags.
Deduplicate P-101 without losing the removed-tag record.
Do not infer where L-10 connects.