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# CVAttachmentModePreference

Defines preferred mode for an attachment key.

```
protocol CVAttachmentModePreference : Sendable
```

## Overview

This protocol is used to identify the mode preferences in generic context. You should use one of the
[`CVAttachmentModePreferenceShouldPropagate`](/documentation/CoreVideo/CVAttachmentModePreferenceShouldPropagate) or [`CVAttachmentModePreferenceShouldNotPropagate`](/documentation/CoreVideo/CVAttachmentModePreferenceShouldNotPropagate) instead of
defining a custom conformance to this protocol.

## Topics

### Type Properties

[`static var preferredMode: CVAttachmentMode`](/documentation/CoreVideo/CVAttachmentModePreference/preferredMode)

## Relationships

### Inherits From

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

[`Sendable`](/documentation/Swift/Sendable)

### Conforming Types

[`CVAttachmentModePreferenceShouldNotPropagate`](/documentation/CoreVideo/CVAttachmentModePreferenceShouldNotPropagate)

[`CVAttachmentModePreferenceShouldPropagate`](/documentation/CoreVideo/CVAttachmentModePreferenceShouldPropagate)

---

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