From Han Wiki
| - Split screen
Tab - Next to the next screen in a split screen
c - Create a new window
C-a A - Rename the screen
C-a C-a - Go back to the previous window
C-a <0-9> - Switch to screen #0-9 (quick toggle)
C-a " - View a list of the current screens, which will allow you to select one from the list
C-a ' - Enter a screen number to switch to (slower version of C-a <0-9>)
C-a d - Detach the whole screen session and fork to the background. Very useful for remote sessions you want to leave open. The command "screen -r" will resume your screen session.
C-a <Escape> - Scroll up through your command line "history" and see what output you previously got. Hitting <Escape> again cancels it.
Ctrl+a : clear-history - clear history in the viewing buffer