The LINE NUMBER clause specifies vertical positioning information for
  a report group, or specifies the vertical screen coordinate for a
  screen item.

1  –  1format_report_description

  Format -

   LINE NUMBER IS { line-num [ON NEXT PAGE] }
                  { PLUS line-num-plus      }

1.1  –  line-num

  is a nonnegative integer.  Line-num represents an absolute line
  number on a logical page and establishes a print line for a Report
  Writer report group.

1.2  –  line-num-plus

  is a positive integer.  Line-num-plus represents a relative line
  number on a logical page and establishes a print line for a Report
  Writer report group.

2  –  2format_screen_description

  Format 2 - Screen Description

   LINE NUMBER IS [PLUS] { identifier-1 }
                         { integer-1    }

2.1  –  identifier-1

  is an elementary unsigned numeric integer data item.  It cannot be
  subscripted.

2.2  –  integer-1

  is an unsigned integer value.