The hotlist edit buffer offers a means to manage a list of frequently used servers. Commands are available in the context pop-up menu generally bound to the right mouse button. Those commands also have equivalent key bindings.
Bound to a. Add a new server to the hotlist on the line after point
Bound to s. Select the server the point is on as the current directory server for the next queries
Bound to t. Bubble up the server the point is on to the top of the list