Width-In-Cells
This style implies that the value specified for the Size property, the one setting the List-Box control’s width, is expressed in CELLS. It is possible to get the same result writing: "Size value CELLS".
 
Example - Define a list-box with height and width in cells
screen section.
...
  03 screen-1-lb-1 List-Box
     height-in-cells
     width-in-cells
     line 5.7
     column 3.1
     size 34.6 
     lines 15.5 
     id 1
     .