With version 2.4.0, Mustang now also supports Order-X.

So far, Mustangproject could read, write and validate XRechnung(CII) and Factur-X/ZUGFeRD invoices as well as
validate Order-X files. Now it can also read and write those orders.

If ERP vendors use the Mustang library to create electronic orders, they can now also use it to
compare invoices to their respective referenced orders: if the order has already been pre-processed and the
fulfillment of the services has been registered, the arrival of a matching invoice referring to the order
can now automatically trigger automatic payment and booking.

Additionally some minor issues have been fixed and the XRechnung has been updated to version
2.1.1 required for german B2G invoices as of February 1st, 2022.