Can someone define a technical term for me?

[Rinehart]

The term is "equalization pulse". I know that blanking pulses raise the grid voltage in a picture tube to the reference black level so that we don't see the vertical or horizontal retrace. Synch pulses exist to keep the vertical and horizontal time bases in step with each other, but I can't figure out what purpose equalization pulses serve. They only occur at the bottom of a television field and the top of the subsequent one, and they run at twice the line rate. Can anyone help?