1 RENAME
  Syntax: RENAME id1 [&idb1] id2 [&idb2]
   where: id1   is the input identifier
          idb1  is the (optional) input secondary identifier
          id2   is the output identifier
          idb2  is the (optional) output secondary identifier

  Renames a plot. If you omit a secondary identifier, the default is used.
  Use the `SET IDB'  command to change the  default. If you give `id1' and
  `id2 = 0' all the plots with secondary identifier `idb1' will be renamed
  to have secondary identifier `idb2'.

  Note that `RENAME' only copies the Mn_Fit histogram and not any
  associated HBOOK historam. Use the `HRENAME' command to copy the HBOOK
  histogram also.

