var productionNumber: String?
ProductionNumber - serial number uniquely identifies instance of the Installation. It represents production number of cash register according to Swedish regulations. It has format "{softwareId}{number}". It must be unique number through the entire world
According to swedish regulation, the definition is: Each cash register must have a production number. Production number is a globally unique serial number on physical cash registers. Production number has to be unique for each cash register from one vendor and should also indicate vendor as a part of the field.