(Num) These coordinates specify the position and size of the control, using traditional row/col units. If the parentid parameter specifies a valid parent control (such as a groupbox, tab, or dialog box), then these coordinates are taken to be relative to the upper left corner of the client area of the parent control.
Even though we are not otherwise bound by the traditional text mode rule of one character per row/col cell, by fitting the control boundaries on to the same coordinate system, it is much easier to migrate from, or maintain compatibility with, legacy text applications.
