The syntax of a type declaration within a record structure is
  identical to that of a normal Fortran type declaration statement:
  it includes a data type (for example, INTEGER), one or more names
  of variables or arrays; and optionally, one or more data
  initialization values.

  The following rules and behavior apply to type declarations in
  record structures:

   o  %FILL can be specified in place of a field name to leave space
      in a record for purposes such as alignment.  This creates an
      unnamed field.

      %FILL can have an array declarator; for example:

         INTEGER %FILL (2,2)

      Unnamed fields cannot be initialized.  For example, the
      following statement is invalid and generates an error message:

         INTEGER*4 %FILL /1980/

   o  Initial values can be supplied in field declaration statements.
      These initial values are supplied for all records that are
      declared using this structure.  Fields not initialized will
      have undefined values when variables are declared by means of
      RECORD statements.  Unnamed fields cannot be initialized; they
      are always undefined.

   o  Field names must always be given explicit data types.  The
      IMPLICIT statement has no effect on statements within a
      structure declaration.

   o  All Fortran data types are allowed in field declarations.

   o  Any required array dimensions must be specified in the field
      declaration statements.  DIMENSION statements cannot be used to
      define field names.

   o  Adjustable or assumed sized arrays and passed-length CHARACTER
      declarations are not allowed in field declarations.

   o  Field names within the same declaration level must be unique,
      but an inner structure declaration (substructure declaration)
      can include field names used in an outer structure declaration
      without conflict.