Ampersand_Versus_Apostrophe_Substitution

   You can use ampersand (&) substitution as opposed to apostrophe
   substitution, to preserve case during traditional parsing.

   The following traditional parsing example shows a series of
   commands that change the case of a character string:

          $ set process/parse_style=traditional
          $ x = "string"
          $ define y 'x'
          $ sho log y
             "Y" = "STRING" (LNM$PROCESS_TABLE)
          $ define y &x
          %DCL-I-SUPERSEDE, previous value of Y has been superseded
          $ sho log y
             "Y" = "string" (LNM$PROCESS_TABLE)

   Note that the use of the ampersand (&) preserved the case of the
   character string assigned to the x variable.