ALPHABET name clause.

Format.

  	  ALPHABET alphabet-name-1 [ IS ]
  	  	  { { STANDARD-1 }			      }
  	  	  { { STANDARD-2 }			      }
  	  	  { { NATIVE     }			      }
  	  	  { { ASCII      }			      }
  	  	  { { EBCDIC     }			      } ...
		  { 	      [ { THROUGH } literal-2 ]       }
		  { literal-1 [ { THRU    }           ] } ... }
		  {	      [			      ]       }
		  {	      [ ALSO literal-3        ]       }