IT and technology
XRechnung
In short and in plain language
XRechnung is a German format for bills sent as a pure data file.
A program can read the data straight away.
For people there are tools that show the bill.
Definition
XRechnung is a German standard for electronic invoices in which the invoice is transmitted as a pure XML data record. It implements the European standard for e-invoices. It is mainly read by software; viewer programs display it for people.