---
title: categoryIdentifier
framework: usernotifications
role: symbol
role_heading: Instance Property
path: usernotifications/unnotificationcontent/categoryidentifier
---

# categoryIdentifier

The identifier of the notification’s category.

## Declaration

```swift
var categoryIdentifier: String { get }
```

## Discussion

Discussion Use notification types to distinguish between the different types of notifications your app supports. You use this support primarily to create actionable notifications with custom action buttons, and to redirect your notifications through either your notification service app extension or your notification content app extension. For remote notifications, the system sets this property to the value of the category key in the aps dictionary.

## See Also

### Retrieving group information

- [threadIdentifier](usernotifications/unnotificationcontent/threadidentifier.md)
- [summaryArgument](usernotifications/unnotificationcontent/summaryargument.md)
- [summaryArgumentCount](usernotifications/unnotificationcontent/summaryargumentcount.md)