# Metadata Identifier Error Codes Error codes that indicate metadata identifier errors. ## Topics ### Constants [`var kCMMetadataIdentifierError_AllocationFailed: OSStatus`](/documentation/CoreMedia/kCMMetadataIdentifierError_AllocationFailed) An error that indicates an allocation fails. [`var kCMMetadataIdentifierError_BadIdentifier: OSStatus`](/documentation/CoreMedia/kCMMetadataIdentifierError_BadIdentifier) An error that indicates the identifier isn’t valid. [`var kCMMetadataIdentifierError_BadKey: OSStatus`](/documentation/CoreMedia/kCMMetadataIdentifierError_BadKey) An error that indicates a key isn’t valid. [`var kCMMetadataIdentifierError_BadKeyLength: OSStatus`](/documentation/CoreMedia/kCMMetadataIdentifierError_BadKeyLength) An error that indicates that a key doesn’t have the correct length. [`var kCMMetadataIdentifierError_BadKeySpace: OSStatus`](/documentation/CoreMedia/kCMMetadataIdentifierError_BadKeySpace) An error that indicates the keyspace isn’t valid. [`var kCMMetadataIdentifierError_BadKeyType: OSStatus`](/documentation/CoreMedia/kCMMetadataIdentifierError_BadKeyType) An error that indicates a key has a bad type. [`var kCMMetadataIdentifierError_BadNumberKey: OSStatus`](/documentation/CoreMedia/kCMMetadataIdentifierError_BadNumberKey) An error that indicates the number for a key isn’t valid. [`var kCMMetadataIdentifierError_NoKeyValueAvailable: OSStatus`](/documentation/CoreMedia/kCMMetadataIdentifierError_NoKeyValueAvailable) An error that indicates a request for a key value in the anonymous keyspace. [`var kCMMetadataIdentifierError_RequiredParameterMissing: OSStatus`](/documentation/CoreMedia/kCMMetadataIdentifierError_RequiredParameterMissing) An error that indicates a parameter the function requires is empty. --- 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)