---
title: UNNotificationAttachmentOptionsTypeHintKey
framework: usernotifications
role: symbol
role_heading: Global Variable
path: usernotifications/unnotificationattachmentoptionstypehintkey
---

# UNNotificationAttachmentOptionsTypeHintKey

A hint about an attachment’s file type.

## Declaration

```swift
let UNNotificationAttachmentOptionsTypeHintKey: String
```

## Discussion

Discussion The value of this key is an NSString containing a Uniform Type Identifier (UTI) that describes the file’s type. If you don’t include this key, the system uses the attachment’s filename extension to determine its type.

## See Also

### Creating an Attachment

- [init(identifier:url:options:)](usernotifications/unnotificationattachment/init(identifier:url:options:)-83grx.md)
- [UNNotificationAttachmentOptionsThumbnailHiddenKey](usernotifications/unnotificationattachmentoptionsthumbnailhiddenkey.md)
- [UNNotificationAttachmentOptionsThumbnailClippingRectKey](usernotifications/unnotificationattachmentoptionsthumbnailclippingrectkey.md)
- [UNNotificationAttachmentOptionsThumbnailTimeKey](usernotifications/unnotificationattachmentoptionsthumbnailtimekey.md)