---
title: systemID
framework: foundation
role: symbol
role_heading: Instance Property
path: foundation/xmldtdnode/systemid
---

# systemID

Returns the system identifier associated with the receiver.

## Declaration

```swift
var systemID: String? { get set }
```

## Return Value

Return Value The system identifier associated with the receiver.

## See Also

### Managing DTD Identifiers

- [isExternal](foundation/xmldtdnode/isexternal.md)
- [notationName](foundation/xmldtdnode/notationname.md)
- [publicID](foundation/xmldtdnode/publicid.md)