---
title: subsystem
framework: OSLog
role: symbol
role_heading: Instance Property
platforms: [iOS 15.0+, iPadOS 15.0+, Mac Catalyst 15.0+, macOS 10.15+, tvOS 15.0+, visionOS 1.0+, watchOS 8.0+]
path: oslog/oslogentrywithpayload/subsystem
---

# subsystem

The payload’s subsystem.

## Declaration

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

## Discussion

Discussion The category is derived from the os_log_t handle used.

## See Also

### Elements of a Payload

- [category](oslog/oslogentrywithpayload/category.md)
- [components](oslog/oslogentrywithpayload/components.md)
- [formatString](oslog/oslogentrywithpayload/formatstring.md)