---
title: asyncRefCon
framework: coreservices
role: symbol
role_heading: Instance Property
path: coreservices/lslaunchfsrefspec/1450600-asyncrefcon
---

# asyncRefCon

A pointer to an arbitrary application-definedvalue, passed in the Carbon event notifying you of an application’slaunch or termination (if you have registered for such notification).The value of this field can be NULL.

## Declaration

```swift
var asyncRefCon: UnsafeMutableRawPointer!
```