---
title: "FormatManager..::.UnknownBeforeOpenFormat Field"
canonical: https://www.graphicsmill.com/docs/gm5/F_Aurigma_GraphicsMill_Codecs_FormatManager_UnknownBeforeOpenFormat.htm
product: "Graphics Mill 5.5 for .NET"
---

This documentation is for the old version. [Go to the latest Graphics Mill docs](https://www.graphicsmill.com/docs/gm/)

# FormatManager.UnknownBeforeOpenFormat Field
 
"Dummy" ID of an unknown format which is used before the stream is opened.
 
**Namespace:** [Aurigma.GraphicsMill.Codecs](https://www.graphicsmill.com/docs/gm5/N_Aurigma_GraphicsMill_Codecs.htm.md)
 **Assembly:** Aurigma.GraphicsMill (in Aurigma.GraphicsMill.dll)
   
## See Also

### Reference

- [FormatManager Class](https://www.graphicsmill.com/docs/gm5/T_Aurigma_GraphicsMill_Codecs_FormatManager.htm.md)
- [Aurigma.GraphicsMill.Codecs Namespace](https://www.graphicsmill.com/docs/gm5/N_Aurigma_GraphicsMill_Codecs.htm.md)