---
title: unknown
framework: avfoundation
role: symbol
role_heading: Type Property
path: avfoundation/avmetadataformat/unknown
---

# unknown

An unknown metadata format.

## Declaration

```swift
static let unknown: AVMetadataFormat
```

## See Also

### Metadata formats

- [hlsMetadata](avfoundation/avmetadataformat/hlsmetadata.md)
- [iTunesMetadata](avfoundation/avmetadataformat/itunesmetadata.md)
- [id3Metadata](avfoundation/avmetadataformat/id3metadata.md)
- [isoUserData](avfoundation/avmetadataformat/isouserdata.md)
- [quickTimeMetadata](avfoundation/avmetadataformat/quicktimemetadata.md)
- [quickTimeUserData](avfoundation/avmetadataformat/quicktimeuserdata.md)