# SourceFileName

Property in [Declaration](https://docs.yarnspinner.dev/api/csharp/yarn.compiler/yarn.compiler.declaration)

## Summary

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

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

## Remarks

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