{% docs backfill_status %}
A status indicator describing whether historical data for this program or IDL has been fully backfilled. Common values: 'complete', 'in_progress', 'not_started'.

**Example:**
- "complete"
- "in_progress"
- "not_started"

**Business Context:**
- Supports data completeness checks, ETL monitoring, and analytics on historical coverage.
{% enddocs %}