This statement is similar to the one discussed in Help topic:
  Statements PARAMETER; they both assign a symbolic name to a
  constant.  However, this PARAMETER statement differs from the other
  one in the following two ways:  its list is not bounded with
  parentheses; and the form of the constant, rather than implicit or
  explicit typing of the symbolic name, determines the data type of
  the variable.  Statement format:

     PARAMETER p=c [,p=c]...

     p  Is a symbolic name.

     c  Is a constant, the symbolic name of a constant, or a
        compile-time constant expression.