An NMMGR screen is 24 lines long. If your terminal
screen is longer than 24 lines, the NMMGR function key labels on
some (older) screens appear to be four lines tall with blank labels
on the bottom two lines. These lines are blank because the functions
assigned by NMMGR clear any existing functions, although blank labels
may still appear on the screen. The function keys on more recently
added NMMGR screens, which store their function key information
in a different way, will appear as normal softkeys, on two lines.