# init(elementKind:handler:) Creates a supplementary registration for the specified element kind with a registration handler. ``` init(elementKind: String, handler: @escaping UICollectionView.SupplementaryRegistration.Handler) ``` --- 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)