/sys$common/syshlp/helplib.hlb FORTRAN, Data, Variables, Implication  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  In the absence of either IMPLICIT statements or explicit type
  statements, all variables with names beginning with I, J, K, L, M,
  or N are assumed to be integer variables.  Variables beginning with
  any other letter are assumed to be REAL*4 variables.