Section 9,1,5: Informational_Messages

 Not an error message and does not call for corrective action.
 However, the informational message informs you that either a
 correct DEC Fortran statement may have unexpected results or you
 have used a DEC Fortran extension to FORTRAN-77.

 The informational messages follow (in alphabetical order):

  o  MESSAGE:  Default STATUS='UNKNOWN' used in OPEN statement

     EXPLANATION:  The OPEN statement default STATUS='UNKNOWN' may
     cause an old file to be inadvertently modified.

  o  MESSAGE:  Do loop increment is 0

     EXPLANATION:  The value of the DO loop increment was zero.

  o  MESSAGE:  Duplicate IDENT ignored

     EXPLANATION:  Two or more CDEC$ IDENT directives were used in a
     source module to specify the identification field of the object
     module.  The first CDEC$ IDENT directive is used.

  o  MESSAGE:  Extension to FORTRAN-77:  Character required

     EXPLANATION:  A character variable was initialized with a
     noncharacter value by means of a DATA statement.

  o  MESSAGE:  Extension to FORTRAN-77:  Concatenation of dummy
     argument

     EXPLANATION:  A character dummy argument appeared as an operand
     in a concatenation operation.

  o  MESSAGE:  Extension to FORTRAN-77:  DATA statement out of order

     EXPLANATION:  A DATA statement occurred prior to a declaration
     statement.  All DATA statements must occur after the
     declaration section of a program.

  o  MESSAGE:  Extension to FORTRAN-77:  Function or Entry name
     undefined

     EXPLANATION:  A value was not assigned to either the function
     name or the entry point name within the body of the function.

  o  MESSAGE:  Extension to FORTRAN-77:  Integer expression required

     EXPLANATION:  One of the following items was not of type
     integer:

        - Logical unit number
        - Record specifier, REC=recspec
        - Arithmetic expression of a computed GOTO statement
        - RETURN [I]
        - Subscript expression
        - Array dimension bounds
        - Character substring bounds expressions

  o  MESSAGE:  Extension to FORTRAN-77:  Logical expression required

     EXPLANATION:  One of the following syntax extensions was
     detected:

        - Numeric expression in a logical IF statement
        - Numeric expression in a block IF statement
        - Value other than .TRUE. or .FALSE. assigned to a 
          logical variable
        - Logical variable initialized with a nonlogical value 
          by means of a DATA statement

  o  MESSAGE:  Extension to FORTRAN-77:  Missing array subscripts

     EXPLANATION:  Only one subscript was used to reference a
     multidimensional array in an EQUIVALENCE statement.

  o  MESSAGE:  Extension to FORTRAN-77:  Mixed numeric and character
     elements in COMMON

     EXPLANATION:  A common block must not contain both numeric and
     character data.

  o  MESSAGE:  Extension to FORTRAN-77:  Mixed numeric and character
     elements in EQUIVALENCE

     EXPLANATION:  A numeric variable or numeric array element
     cannot be equivalenced to a character variable or character
     array element.

  o  MESSAGE:  Extension to FORTRAN-77:  More than 19 continuation
     lines

     EXPLANATION:  More than 19 continuation lines were defined for
     the statement.

  o  MESSAGE:  Extension to FORTRAN-77:  Negative implied-DO
     iteration count

     EXPLANATION:  The iteration count of an implied DO was
     negative.

  o  MESSAGE:  Extension to FORTRAN-77:  Nonstandard branch into
     block

     EXPLANATION:  A nonstandard branch into a DO loop or IF block
     was detected.

  o  MESSAGE:  Extension to FORTRAN-77:  nonstandard comment

     EXPLANATION:  FORTRAN-77 allows only the characters "C" and "*"
     to begin a comment line; "c", "D", "d", and "!" are extensions
     to FORTRAN-77.

  o  MESSAGE:  Extension to FORTRAN-77:  nonstandard constant

     EXPLANATION:  The following constant forms are extensions to
     FORTRAN-77:

        Form                     Example
        ----                     -------
        Hollerith                nH.....
        Typeless                 'xxxx'X or 'oooo'O
        Hexadecimal              Zxxxx
        Complex with 
           PARAMETER components
        COMPLEX*16              (www.xxxDn, yyy.zzzDn)

  o  MESSAGE:  Extension to FORTRAN-77:  nonstandard continuation
     character

     EXPLANATION:  A nonstandard character was used as a
     continuation indicator.

  o  MESSAGE:  Extension to FORTRAN-77; nonstandard data type
     specification

     EXPLANATION:  The following DATA type specifications are
     extensions to FORTRAN-77.  The FORTRAN-77 equivalent is given
     where available.  This message is issued when these types are
     used in the IMPLICIT statement or in a numeric type statement.

        Extension       Standard
        ---------       --------
        BYTE               --
        LOGICAL*1          --
        LOGICAL*2       LOGICAL (with -noi4 specified)
        LOGICAL*4       LOGICAL
        INTEGER*1          --
        INTEGER*2       INTEGER (with -noi4 specified)
        INTEGER*4       INTEGER
        REAL*4          REAL
        REAL*8          DOUBLE PRECISION
        COMPLEX*8       COMPLEX
        COMPLEX*16         --
        DOUBLE COMPLEX     --

  o  MESSAGE:  Extension to FORTRAN-77:  Nonstandard DATA
     initialization

     EXPLANATION:  An element was initialized in either of the
     following ways:

        - In a blank common block
        - Outside the BLOCK DATA structure (and the element 
          is in a named COMMON block)

  o  MESSAGE:  Extension to FORTRAN-77:  nonstandard FORMAT
     statement item

     EXPLANATION:  The following format field descriptors are
     extensions to FORTRAN-77:

        Descriptor      Aspect
        ----------      ------
            $           All forms
        A,L,I,F,E,G,D   Default field width forms
            P           Without scale factor

  o  MESSAGE:  Extension to FORTRAN-77:  Nonstandard function return
     type

     EXPLANATION:  A function or entry point was declared with a
     nonstandard data type.

  o  MESSAGE:  Extension to FORTRAN-77:  nonstandard intrinsic
     function

     EXPLANATION:  A nonstandard intrinsic function was used.

  o  MESSAGE:  Extension to FORTRAN-77:  nonstandard keyword

     EXPLANATION:  A nonstandard keyword was used.

  o  MESSAGE:  Extension to FORTRAN-77:  nonstandard lexical item

     EXPLANATION:  One of the following nonstandard lexical items
     was used:

        - Alternate return specifier with an ampersand (&)
          in a CALL statement
        - Apostrophe (') form of record specifier in a direct 
          access I/O statement
        - Variable format expression

  o  MESSAGE:  Extension to FORTRAN-77:  Nonstandard loop expression

     EXPLANATION:  The upper-bound expression, lower-bound
     expression, or increment expression of a DO loop was not of
     type integer, real, or double precision.

  o  MESSAGE:  Extension to FORTRAN-77:  nonstandard name

     EXPLANATION:  A name longer than six characters or one that
     contained a dollar sign ($) or an underscore (_) was used.

  o  MESSAGE:  Extension to FORTRAN-77:  nonstandard operator

     EXPLANATION:  The operators .XOR., %VAL, %REF, and %LOC are
     extensions to FORTRAN-77.  The standard form of .XOR.  is
     .NEQV.  The % operators are extensions provided to allow access
     to non-FORTRAN parts of the VMS environment.

  o  MESSAGE:  Extension to FORTRAN-77:  nonstandard statement type

     EXPLANATION:  A nonstandard statement type was used.

  o  MESSAGE:  Extension to FORTRAN-77:  nonstandard syntax

     EXPLANATION:  One of the following syntax extensions was
     specified:

        PARAMETER name = value --> Error: No parentheses
        
        type name/value/       --> Error: Data initialization in
                                          type declaration
        
        DATA (ch(exp1:exp2),i=lb,ub,inc)/values/) 
                               --> Error:Substring initialization with 
                                         implied-DO in DATA statement
        
        CALL name(arg2,,arg3)  --> Error: Null actual argument
        
        READ (...),iolist      --> Error: Comma between I/O control 
                                          and element lists
        
        PARAMETER (name2=ABS(name1)) --> Error: Function use in 
                                                PARAMETER statement
        
        e1 ** -e2              --> Error: Two consecutive operators

  o  MESSAGE:  Extension to FORTRAN-77:  Nonstandard use of array

     EXPLANATION:  One of the following extensions was detected:

        - An array was used as a FILE specification in an 
          OPEN statement.
        - The file name of an INQUIRE statement was a numeric 
          scalar reference or a numeric array name reference.

  o  MESSAGE:  Extension to FORTRAN-77:  Nonstandard use of field
     reference

     EXPLANATION:  A record reference (for example,
     record-name.field-name) was used in a program compiled with
     -stand syntax.

  o  MESSAGE:  Extension to FORTRAN-77:  tab indentation or
     lowercase source

     EXPLANATION:  The use of tab indentation or lowercase letters
     in source code is an extension to FORTRAN-77.

  o  MESSAGE:  Invalid qualifier or qualifier value in OPTIONS
     statement

     EXPLANATION:  An invalid qualifier or qualifier value was
     specified in the OPTIONS statement.  When this error is
     encountered, the qualifier is ignored.

  o  MESSAGE:  No path to this statement

     EXPLANATION:  Program control could not reach this statement.
     When this situation occurs, the statement is deleted.  For
     example:

        10   I = I + 1
             GO TO 10
             STOP

     You can disable this message by compiling with -warn
     nounreachable.

  o  MESSAGE:  Not yet implemented

     EXPLANATION:  The specified feature has not been implemented.

  o  MESSAGE:  Routine xxx does not return a value

     EXPLANATION:  A subroutine which doesn't return a value was
     used where a value is expected.  For example:

        T = SUB(J)
        ...
        SUBROUTINE SUB(I)

  o  MESSAGE:  Statement function xxx is never called

     EXPLANATION:  A statement function (named xxx) was declared but
     never used.  This could be caused by a missing DIMENSION
     statement that caused a variable assignment to be interpreted
     as a statement function.

     You can disable this message by compiling with -warn
     nouncalled.

  o  MESSAGE:  Unrecognized directive ignored

     EXPLANATION:  A directive was detected in the first five
     columns of a source code statement.  The directive was not
     recognized or the remainder of the directive contains illegal
     syntax.