With the release of the new user manual „Decision tree diagrams and code lists for responses“, format changes will be introduced on 01/04/2021 with fixed specifications regarding check sequences and new response codes. This will be accompanied by procedural changes for existing processes GPKE, WiM, MPES and MaBiS. These changes will increases the complexity of replying to message – and the check specifications do not apply uniformly for all processes. Differentiation between divisions is required. Furthermore, the DTDs to be used for each process must be specified in the response message. The format of the codes in the messages will also change. With new and existing response codes that do not have a uniform meaning, the result is total chaos. These specifications will lead to far-reaching changes in all affected market processes and ultimately in your IT systems.