I concur with support for the decision in RFC 5952 to establish a
canonical format for IPv6 addresses. The choice of lower-case was
deliberate and subject to review and consensus within the working group,
and should not be construed as an "erratum". Opinions and
implementations may vary. "Harm" in non-conformance is minor, resulting
in more complex processing of textual output as input to another
system. The canonical format was intended to to make such textual
output from various implementations to be comparable, for merging and
sorting in reports, etc. Personally, I would code defensively (liberal
in what I accept from other systems) while respecting the canonical
format for my output (conservative in what I do) [RFC793].
On 12/2/2010 4:17 PM, RFC Errata System wrote:
The following errata report has been submitted for RFC5952,
"A Recommendation for IPv6 Address Text Representation".
--------------------------------------
You may review the report below and at:
http://www.rfc-editor.org/errata_search.php?rfc=5952&eid=2656
--------------------------------------
Type: Technical
Reported by: D. Stussy<d.stu...@yahoo.com>
Section: 4.3
Original Text
-------------
4.3. Lowercase
The characters "a", "b", "c", "d", "e", and "f" in an IPv6 address
MUST be represented in lowercase.
Corrected Text
--------------
4.3. Case of Alphabetic Digits.
The digits "A" through "F" in an IPv6 address
MUST be represented in upper case. User and user
derived input may be represented using lower case.
Notes
-----
Historically from the 1960's, hexidecimal digits other than decimal digits are
represented by upper case letters. Lower case letters may have become
acceptable as user input, but such resulted from lazy programmers who couldn't
manage to hit the shift key on their keyboards. However, lower case is not
acceptable for digit output. Many early assemblers would not even accept lower
case as valid input digits except where the radix base exceeded 36 (thus
exhausting all upper case values). This poor programming practice should not
be allowed to be codified into any Internet standard.
References:
- Struble, George W., "Assembler Language Programming: The IBM System/360 and
/370." Addison-Wesley Publishing Co., 1969 and 1975 (Second Edition), Page 6. ISBN
0-201-7322-6
- Barden, William Jr., "TRS-80 Assembly-Language Programming." Tandy
Corporation, 1979, page 14. Library of Congress #79-63607
- Leventhal, Lance A., "6502 Assembly Language Programming." Osborne
McGraw-Hill, 1979 and 1986 (Second Edition), Page 1-4. ISBN 0-07-881216-X
- Intel Corporation, "Intel486 Microprocessor Family Programmer's Reference
Manual." 1995, Page 1-8 (Section 1.3.4). No ISBN or LoC #.
- Cress, Paul, Dirksen, Paul, and Grahm, J. Wesley, "Fortran IV with WatFor and
WatFiv." Prentice-Hall, 1968 and 1970, Page 245. LoC 74-129241
- Mano, M. Morris, "Computer System Architecture." Prentice-Hall, 1982, Page
79. ISBN 0-13-166611-8
- Higgins, Richard J., "Electronics with Digital and Analog Integrated
Circuits." Prentice-Hall, 1983, Page 60. ISBN 0-13-250704-8
However, I also note this ONE source permits mixed case:
- Kernighan, Brian W.& Ritchie, Dennis M., "The C Programming Language",
Prentice Hall, 1978 (First Edition), Page 180. ISBN 0-13-110163-3
Many other pre-1990 computer science and engineering books show hexidecimal
non-decimal digits as upper case only and NEVER as lower case. However, I
could not find pages in them defining the lettered-digits as upper case only
despite their consistent usage of upper case printing.
Instructions:
-------------
This errata is currently posted as "Reported". If necessary, please
use "Reply All" to discuss whether it should be verified or
rejected. When a decision is reached, the verifying party (IESG)
can log in to change the status and edit the report, if necessary.
--------------------------------------
RFC5952 (draft-ietf-6man-text-addr-representation-07)
--------------------------------------
Title : A Recommendation for IPv6 Address Text Representation
Publication Date : August 2010
Author(s) : S. Kawamura, M. Kawashima
Category : PROPOSED STANDARD
Source : IPv6 Maintenance
Area : Internet
Stream : IETF
Verifying Party : IESG
--------------------------------------------------------------------
IETF IPv6 working group mailing list
ipv6@ietf.org
Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6
--------------------------------------------------------------------
--
Ed Jankiewicz - SRI International
Fort Monmouth Branch Office - IPv6 Research
Supporting DISA Standards Engineering Branch
732-389-1003 or ed.jankiew...@sri.com
--------------------------------------------------------------------
IETF IPv6 working group mailing list
ipv6@ietf.org
Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6
--------------------------------------------------------------------
