I am unsure of the right usage, which is quite a basic question admittedly.
I assume that it works the following way : to address several people, whether there is a mark of reverence/politeness or not we say
Tenetemi informato
to address one person we are close to we say
Tienimi informato
and to address one person with a mark of reverence/politeness we say
Tengami informato
Is the assumption correct, or what is the right imperative construction for the various cases?