PARAMETER statements:  PARAMETER statements can appear in a
  structure declaration, but cannot be given a data type within the
  declaration block.  Consider the following:

     STRUCTURE /ABC/
         INTEGER*4 P
         PARAMETER (P=4)
         REAL*4 F
     END STRUCTURE
         REAL*4 A(P)

  In this example, the INTEGER*4 statement does not provide the data
  type for PARAMETER constant P, but instead declares a record field
  P in structure ABC.  The subsequent PARAMETER statement declares a
  new, different symbol which is given the implicit data type for
  identifiers beginning with the letter P.

  Type declarations for PARAMETER symbolic names must precede the
  PARAMETER statement and be outside of a STRUCTURE declaration, as
  follows:

         INTEGER*4 P
     STRUCTURE /ABC/
         PARAMETER (P=4)
         REAL*4 F
     END STRUCTURE
         REAL*4 A(P)

  For more information on PARAMETER statements, see STATEMENTS
  PARAMETER in this Help file.