Section 10,5: Reversion

 When the last closing parenthesis of the format specification is
 reached, format control determines whether more I/O list elements
 are to be processed.  If not, format control terminates.  However,
 if additional list elements remain, part or all of the format
 specification is reused in a process called format reversion.

 In format reversion, the current record is terminated, a new one is
 initiated, and format control reverts to the group repeat
 specification whose opening parenthesis matches the next-to-last
 closing parenthesis of the format specification.  If the format
 does not contain a group repeat specification, format control
 returns to the initial opening parenthesis of the format
 specification.  Format control continues from that point.