---
title: CMIOExtensionInfoDictionaryKey
framework: coremediaio
role: symbol
role_heading: Global Variable
path: coremediaio/cmioextensioninfodictionarykey
---

# CMIOExtensionInfoDictionaryKey

A key that specifies the extension information dictionary.

## Declaration

```swift
let CMIOExtensionInfoDictionaryKey: String
```

## See Also

### Properties

- [CMIOExtensionProperty](coremediaio/cmioextensionproperty.md)
- [CMIOExtensionPropertyState](coremediaio/cmioextensionpropertystate.md)
- [CMIOExtensionPropertyAttributes](coremediaio/cmioextensionpropertyattributes.md)
- [CMIOExtensionMachServiceNameKey](coremediaio/cmioextensionmachservicenamekey.md)