---
title: invalid
framework: DeviceDiscoveryExtension
role: symbol
role_heading: Type Property
platforms: [iOS 16.0+, iPadOS 16.0+, Mac Catalyst 16.0+, visionOS 1.0+]
path: devicediscoveryextension/dddeviceprotocolstring/invalid
---

# invalid

A human-readable string for the default device protocol.

## Declaration

```swift
static let invalid: DDDeviceProtocolString
```

## See Also

### Specifying a device protocol string

- [dial](devicediscoveryextension/dddeviceprotocolstring/dial.md)