Full_Description

   If the sort operation is a record or tag sort, the default output
   record format is the same as the first input file record format.
   If the sort operation is an address or index sort, the default
   output record format is fixed record format. If the input files
   have different record formats, Sort provides an output record
   size that is large enough to contain the largest record in the
   input files.

   When you specify the output record format, you can indicate
   the maximum record size, in bytes, of the output records. You
   can specify fixed-length records, variable-length records, or
   variable with fixed-length control records.