Web UI mostly offer only a subset of available options for $object-add commands in adder dialog. It is to have simple and easy to use dialog. But in some specific cases, special option needs to be provided at 'add' time, e.g. --noprivate and --gidnumber #5505 in user add. These special cases clutters up the simple UI.

UI should have a way to provide simple dialog while allowing to specify all other applicable options in, e.g., advanced section.