I discovered this as part of #585, but it's a separate (though related) issue...

The base Client object does not track if a client is confidential (or not), however clients must act differently in certain situations depending on this. It looks like this was largely handled by creating a different base class for each 'concept'. I think adding an is_confidential' property to the base Client` class (and set in the subclasses) would allow for more code re-use and just be generally more descriptive and self-documenting.