1. The LINE NUMBER phrase is used to position the cursor on a specific line or cell row of the terminal. A line number value of one indicates the top line of the current subwindow. To support fine positioning of controls in graphical environments, non-integer values are allowed. On text-mode systems, non-integer values are rounded down to the nearest whole number.
  2. When used with controls and floating windows, the line number positions the top edge of the control or window.
  3. If the LINE NUMBER phrase is missing or zero, then the results depend on the compatibility mode being used.
    1. In VAX COBOL and ICOBOL compatibility modes, the current cursor line is used. This is used in all cases when the statement refers to controls.
    2. In RM/COBOL compatibility mode, the current line is used if the COLUMN phrase specifies a value of zero or the NO ADVANCING phrase is used. Otherwise, the next line is used. In any case, if ERASE is also specified (without EOL or EOS), then line 1 is used instead.
  4. If the line number results in a value greater than the number of lines in the current window, the current window is scrolled up one line, and the line number is set to be the bottom line of the current window.

    This rule does not apply to controls. If a control is positioned outside of the current subwindow, it is not created.

  5. You may use LINE NUMBER with different units, such as CELLS or PIXELS. PIXELS apply only with controls, and not with windows. Non-integer values are allowed with cells, but they are not allowed with pixels.
  6. The LINE NUMBER phrase used for entries in the Screen Section has a different format. See section LINE Clause for details.