Mz3Tool and MegaZine3 make use of several configuration files to save program settings and Mz3 Book parameters.
Although usually not needed (all those parameters are managed automatically in the background), it can be helpful knowing about those files.
A look into such files can help to answer a special question or when a problem has to be nailed down.
Also in case of certain requirements (like an exchange of a parameter on many pages) direct access to such “basic/core data” can offer additional options.
More details can be found in chapter Configuration Files