# UICollectionView.SupplementaryRegistration A registration for the collection view’s supplementary views. ``` struct SupplementaryRegistration where Supplementary : UICollectionReusableView ``` ## Overview Use a supplementary registration to register supplementary views, like headers and footers, with your collection view and configure each view for display. You create a supplementary registration with your supplementary view type and data item type as the registration’s generic parameters, passing in a registration handler to configure the view. In the registration handler, you specify how to configure the content and appearance of that type of supplementary view. The following example creates a supplementary registration for a custom header view subclass. ```swift let headerRegistration = UICollectionView.SupplementaryRegistration (elementKind: "Header") { supplementaryView, string, indexPath in supplementaryView.label.text = "\(string) for section \(indexPath.section)" supplementaryView.backgroundColor = .lightGray } ``` After you create a supplementary registration, you pass it in to [`dequeueConfiguredReusableSupplementary(using:for:)`](/documentation/UIKit/UICollectionView/dequeueConfiguredReusableSupplementary(using:for:)), which you call from your data source’s [`supplementaryViewProvider`](/documentation/UIKit/UICollectionViewDiffableDataSource-9tqpa/supplementaryViewProvider-swift.property). ```swift dataSource.supplementaryViewProvider = { collectionView, elementKind, indexPath in return collectionView.dequeueConfiguredReusableSupplementary(using: headerRegistration, for: indexPath) } ``` You don’t need to call [`register(_:forSupplementaryViewOfKind:withReuseIdentifier:)`](/documentation/UIKit/UICollectionView/register(_:forSupplementaryViewOfKind:withReuseIdentifier:)-661io) or [`register(_:forSupplementaryViewOfKind:withReuseIdentifier:)`](/documentation/UIKit/UICollectionView/register(_:forSupplementaryViewOfKind:withReuseIdentifier:)-9hn73). The registration occurs automatically when you pass the supplementary view registration to [`dequeueConfiguredReusableSupplementary(using:for:)`](/documentation/UIKit/UICollectionView/dequeueConfiguredReusableSupplementary(using:for:)). > Important: > Don’t create your supplementary view registration inside a ``doc://com.apple.uikit/documentation/UIKit/UICollectionViewDiffableDataSource-9tqpa/SupplementaryViewProvider-swift.typealias`` closure; doing so prevents reuse, and generates an exception in iOS 15 and higher. ## Topics ### Creating a supplementary registration [`init(elementKind:handler:)`](/documentation/UIKit/UICollectionView/SupplementaryRegistration/init(elementKind:handler:)) Creates a supplementary registration for the specified element kind with a registration handler. [`init(supplementaryNib:elementKind:handler:)`](/documentation/UIKit/UICollectionView/SupplementaryRegistration/init(supplementaryNib:elementKind:handler:)) Creates a supplementary registration for the specified element kind with a registration handler and nib file. [`UICollectionView.SupplementaryRegistration.Handler`](/documentation/UIKit/UICollectionView/SupplementaryRegistration/Handler) A closure that handles the supplementary view registration and configuration. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)