One can install Notes (normal client), designer (design conception client) and administrator (admin client). There are separated install for every combination of the above.
However, one can activate designer and administrator on a client install by simply adding a file named designer.exe and admin.exe in the PROGDIR of Notes. Notes must be closed. These two files create teh shortcut that make administrator or designer being launchable from the client.
Not, sur it is still the same in 8.5 otherwise you’ll have to install the admin client together with the client.