VMS Help FORTRAN, Statements, IMPLICIT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Defines the type specifications of implicitly defined variables.
  Statement format:

     IMPLICIT typ(a[,a]...)[,typ(a[,a]...)]...

     typ  Is any data type except CHARACTER*(*).  When "typ"
          is equal to CHARACTER*len, "len" specifies the length
          for character data type.  The "len" is an unsigned
          integer constant or an integer constant expression
          enclosed in parentheses, and must be in the range of
          1 to 65535.

     a    Is an alphabetical character.  If you specify a
          range of alphabetic characters (two characters
          joined by a hyphen), the first character must be
          less than the second.

  The IMPLICIT statement assigns the specified data type to all
  symbolic names that have no explicit data type and begins with the
  specified letter or range of letters.  It has no effect on the
  default types of intrinsic procedures.