# AVKit metadata identifiers Additional metadata that an asset contains. ## Topics ### Displayed metadata [`let AVKitMetadataIdentifierExactStartDate: String`](/documentation/AVKit/AVKitMetadataIdentifierExactStartDate) The exact start date for a live event stream. [`let AVKitMetadataIdentifierExactEndDate: String`](/documentation/AVKit/AVKitMetadataIdentifierExactEndDate) The exact end date for a live event stream. [`let AVKitMetadataIdentifierApproximateStartDate: String`](/documentation/AVKit/AVKitMetadataIdentifierApproximateStartDate) The approximate start date for a live event stream. [`let AVKitMetadataIdentifierApproximateEndDate: String`](/documentation/AVKit/AVKitMetadataIdentifierApproximateEndDate) The approximate end date for a live event stream. ### Nondisplayed metadata [`let AVKitMetadataIdentifierPlaybackProgress: String`](/documentation/AVKit/AVKitMetadataIdentifierPlaybackProgress) The playback progress published through the Now Playing Info Center. [`let AVKitMetadataIdentifierExternalContentIdentifier: String`](/documentation/AVKit/AVKitMetadataIdentifierExternalContentIdentifier) The identifier for external content published through the Now Playing Info Center. [`let AVKitMetadataIdentifierExternalUserProfileIdentifier: String`](/documentation/AVKit/AVKitMetadataIdentifierExternalUserProfileIdentifier) The identifier for an external user profile published through the Now Playing Info Center. [`let AVKitMetadataIdentifierServiceIdentifier: String`](/documentation/AVKit/AVKitMetadataIdentifierServiceIdentifier) The service identifier published through the Now Playing Info Center. --- 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)