---
title: Callback Identifiers
framework: corefoundation
role: collectionGroup
role_heading: API Collection
path: corefoundation/1477595-callback-identifiers
---

# Callback Identifiers

Constants that identify the read and write callbacks.

## Topics

### Constants

- [kCFFileDescriptorReadCallBack](corefoundation/kcffiledescriptorreadcallback.md)
- [kCFFileDescriptorWriteCallBack](corefoundation/kcffiledescriptorwritecallback.md)