CENTER LINE
  Centers a line of text between the current margins of the buffer, by
  inserting spaces at the start of the line.
  Key:   The WPS keypad defines GOLD-C as CENTER LINE.
  Steps:
     1.  Put the cursor anywhere on the line you want to center.
     2.  Use the CENTER LINE command or with the WPS keypad, press GOLD-C.
  Usage notes:
  o  The cursor moves with the line, remaining on the same character as the
     text moves. If you are on a blank line, CENTER LINE moves the cursor to
     the center column between the left and right margins.
  o  CENTER LINE deletes tabs or spaces at the start and end of a line---and
     then adds spaces at the start--but does not affect spaces and tabs in
     the middle of a line.
  Related topics:
     SET LEFT MARGIN     SET RIGHT MARGIN