New Web page on supplementary RFC 3066bis codes

Doug Ewell dewell at
Wed Jun 23 08:59:54 CEST 2004

Misha Wolf <Misha dot Wolf at reuters dot com> wrote:

> The page contains one instance of "must not" and two instances of
> "MAY NOT" (caps and underlined).  All three are italicised.  I've
> consulted:
>    Key words for use in RFCs to Indicate Requirement Levels
> and failed to find a definition of "may not".  Please could you
> replace it with "must not".  Please also harmonise your use of case
> and underlining in these three instances.

It hadn't occurred to me to follow RFC 2119 recommendations in this Web
page, but it's an excellent idea, especially if I expect this to be a
working (if unofficial) supplement to RFC 3006bis.  I've made the
suggested changes and eliminated the needless underlining.

Mark Davis <mark dot davis at jtcsv dot com> wrote:

> Nice work!


I should note that the passage explaining UN code 001 ("World") in terms
of "de-001" versus plain "de" was plagiarized from a private e-mail from

I've made some other changes as well.  While standardizing my use of MAY
and MUST NOT, I abandoned the attempt to color-code the charts using the
dominant color of their respective standards' home pages -- you did
notice that, right? -- and replaced it with a greenish tint for allowed
(MAY) codes and a reddish tint for disallowed (MUST NOT) codes.

More importantly, I added information on one of the more important
topics surrounding these "deprecated" codes, the potential equivalence
relationship involving codes that have a direct replacement.  For
example, deprecated "iw" (Hebrew) = modern "he", and deprecated "TP"
(East Timor) = modern "TL" (Timor-Leste, same place).  If this
equivalence thing is to work, there needs to be a complete resource that
implementers can refer to, not just selected examples.

The new version is now available at, once again,

All comments are encouraged, good or bad, editorial or technical.

-Doug Ewell
 Fullerton, California

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