Width-In-Cells
This style implies that the value specified for the 
Size property, the one setting the Scroll-Pane control’s width, is expressed in CELLS. It is possible to get the same result writing: "
Size value CELLS".
 
Example - Define a scroll pane with height and width in cells
screen section. ...   03 screen-1-sp-2 Scroll-pane      line 39.1      column 12.8      size 2.4       lines 30.8      id 10      height-in-cells      width-in-cells      .  |