> For the complete documentation index, see [llms.txt](https://docs.yarnspinner.dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.yarnspinner.dev/api/csharp/yarn.compiler/yarn.compiler.declaration/yarn.compiler.declaration.sourcefilename.md).

# SourceFileName

Property in [Declaration](/api/csharp/yarn.compiler/yarn.compiler.declaration.md)

## Summary

Gets the name of the file in which this Declaration was found.

```csharp
public string SourceFileName { get; internal set; }
```

## Remarks

If this [Declaration](/api/csharp/yarn.compiler/yarn.compiler.declaration.md) was not found in a Yarn source file, this will be [ExternalDeclaration](/api/csharp/yarn.compiler/yarn.compiler.declaration/yarn.compiler.declaration.externaldeclaration.md) .