#A couple of Links useful for XRechnung

Offical Documentation PDF is embedded in the source code (ZUGFeRD-2.1.1 - Spezifikation_TA (1)).  
Here the link for this document in the official Version archive: https://www.ferd-net.de/standards/zugferd-version-archive/zugferd-2.1.html

##Opensource Implementation 
https://github.com/stephanstapel/ZUGFeRD-csharp  
Nice place to check out some Stuff, has a couple of Demo files.  
Would be nice to switch to this in the future instead of creating our own implementation.

##KOSIT (Koordinierungsstelle für IT-Standards)
https://github.com/itplr-kosit  
Different helpful repositories for XRechnung.  
For example a cli tool to verify the xml.