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# allowsRunningApplicationSubstitution

A Boolean value that indicates whether to use a running instance of an application even if it’s at a different URL.

```
var allowsRunningApplicationSubstitution: Bool { get set }
```

## Discussion

If an instance of an application is already running and is capable of opening the provided URLs, but the running instance is at a different URL, use the running application.

This property defaults to <doc://com.apple.documentation/documentation/Swift/true>. Set this to <doc://com.apple.documentation/documentation/Swift/false> if you let the user select between specific versions of an application, or let them choose a particular installation.

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