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# supplementaryContentInsetsReference

The reference boundary for content insets on boundary supplementary items.

```
var supplementaryContentInsetsReference: UIContentInsetsReference { get set }
```

## Discussion

This property represents the reference boundary to use when defining [`contentInsets`](/documentation/UIKit/NSCollectionLayoutItem/contentInsets) on [`NSCollectionLayoutBoundarySupplementaryItem`](/documentation/UIKit/NSCollectionLayoutBoundarySupplementaryItem) objects.

The default value of this property is [`UIContentInsetsReference.automatic`](/documentation/UIKit/UIContentInsetsReference/automatic), which means any insets specified on a [`NSCollectionLayoutBoundarySupplementaryItem`](/documentation/UIKit/NSCollectionLayoutBoundarySupplementaryItem) follow the layout configuration’s [`contentInsetsReference`](/documentation/UIKit/UICollectionViewCompositionalLayoutConfiguration/contentInsetsReference).

---

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