---
title: bFunctionSubClass
framework: IOKit
role: symbol
role_heading: Instance Property
platforms: [Mac Catalyst 13.0+, macOS 10.3+]
path: iokit/iousbinterfaceassociationdescriptor/1426264-bfunctionsubclass
---

# bFunctionSubClass

## Declaration

```occ
uint8_t bFunctionSubClass;
```