In the example above, PROPPOS (4,12) places the control 4 windows units horizontally, and 12 windows units vertically from the upper left-hand corner of the dialog. Or, to put it another way, 4 units to the left of the upper left-hand corner of the dialog, and 12 units down from that corner. PROPSIZE (150,40) makes the control 150 windows units wide and 40 windows units long.
LABELPOS places the label for the control 4 windows units horizontally, and 2 windows units vertically from the upper left-hand corner of the dialog. The label, therefore, is the same distance from the edge of the dialog, but 10 windows units above the control.
A portion of the syntax from SAPROPS.CFG for the Entity Definition dialog follows.