There were many discussions on which letter of the alphabet the recession would end up with:
W: Double dip, two consecutive business cycles
V: Single dip
L: Economy going down and staying there for long.
I think, there is a need for a new letter to show that economy is balancing at lower level of income (macro wise). "F" may be. We can think it in terms of Cartesian coordinates: x the horizontal axis, y the vertical axis and the top horizontal line (x1) of letter F as the level of income before recession and the below horizontal line (x2) as the level after the recession.