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

  A variable is represented by a symbolic name that is associated
  with a storage location.  The value of the variable is the value
  currently stored in that location; the value can be changed by
  assigning a new value to the variable.

  Variables, like constants, are classified by data type.  When data
  of any type is assigned to a variable, it is converted, if
  necessary, to the data type of the variable.  You can establish the
  data type of a variable by type declaration statements, IMPLICIT
  statements, or predefined typing rules.

1 - Implication

  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.

2 - Specification

  Type declaration statements explicitly define the data type of
  variables.

  Numeric type declaration statements have the form:

     type v[/clist][,v[/clist]]...

  type   Is any data type except CHARACTER.

  v      Is the name of a constant, variable, array, statement
         function or function subprogram, or array declarator.

  clist  Is a list of constants.

  Character type declaration statements have the form:

     CHARACTER[*len[,]] v[*len] [/clist/] [,v[*len] [/clist/]]...

  len    Is an unsigned integer constant, an integer constant
         expression enclosed in parentheses, or an asterisk
         enclosed in parentheses.

         The value of len specifies the length of the character
         data elements.

  v      Is the symbolic name of a constant, variable, array,
         statement or function subprogram, or array declarator.

         The name can optionally be followed by a data type
         length specifier (*n).  For character entities, the length
         specifier can be *len or *(*).

  clist  Is an initial value or values to be assigned to the
         immediately preceding variable or array element.