CCdummy functionality of the application is to convert the project (family instances) into "dumb" geometry, where all the parametric values (type/instance) and geometry itself will be preserved but the inner logical connections between parameter values and geometry will be deleted.
This "dumb" geometry can't be edited afterwards and is safe to be sent to another person for collaboration without being in fear of losing your family know-how. The application can also add and copyright to your project, which will be hidden inside the document itself and also in the project information.
After launch. the application will re-save your project into the same folder but with a suffix of _dummed.rvt so you won't lose any data from the original project.