---
title: NSUnknownKeySpecifierError
framework: foundation
role: symbol
role_heading: Global Variable
path: foundation/nsunknownkeyspecifiererror
---

# NSUnknownKeySpecifierError

Receivers do not understand the key.

## Declaration

```swift
var NSUnknownKeySpecifierError: Int { get }
```

## See Also

### Constants

- [NSNoSpecifierError](foundation/nsnospecifiererror.md)
- [NSNoTopLevelContainersSpecifierError](foundation/nsnotoplevelcontainersspecifiererror.md)
- [NSContainerSpecifierError](foundation/nscontainerspecifiererror.md)
- [NSInvalidIndexSpecifierError](foundation/nsinvalidindexspecifiererror.md)
- [NSInternalSpecifierError](foundation/nsinternalspecifiererror.md)
- [NSOperationNotSupportedForKeySpecifierError](foundation/nsoperationnotsupportedforkeyspecifiererror.md)