# `IndicesFieldUsageStatsUsageStatsShards` [interface-IndicesFieldUsageStatsUsageStatsShards] | Name | Type | Description | | - | - | - | | `routing` | [IndicesStatsShardRouting](./IndicesStatsShardRouting.md) |   | | `stats` | [IndicesFieldUsageStatsShardsStats](./IndicesFieldUsageStatsShardsStats.md) |   | | `tracking_id` | string |   | | `tracking_started_at_millis` | [EpochTime](./EpochTime.md)<[UnitMillis](./UnitMillis.md)> |   |