The documentation does not exist as far as I can tell (outside the code itself).
Some controls are just simple wrappers that do localization for you (i.e. just set a property Text, don't use it ResourceKey).
Some controls use the appropriate Telerik control, apply a skin to the control (simple skin plus CSS specific for control from the DNN shell), as well as localization (1) . If you do not have a Telerik license, these wrappers are your only access to the associated Telerik controls.
Some controls are more prescriptive combinations of controls.
, DNN , . , ( ), , , .
(1) , DnnGrid, DNN 5.6.