Michael wrote:
> In other words, all behavior, core and specialized, is
overrideable.
This is the subject of the discussion (item
#4 from my previous note) that we plan to have. The fundamental question that
we need to answer is, is all behavior overrideable, that is, is everything either
RECOMMENDED or OPTIONAL, or are some things truly REQUIRED?
Or stated another way, the core as a whole
is REQUIRED, but individual items within the core may be REQUIRED, RECOMMENDED,
or OPTIONAL with respect to specializations.
This doesn’t really get interesting
until we get down to specific cases and we have to figure out when to use MUST /
REQUIRED, SHOULD / RECOMMENDED, and MAY / OPTIONAL
-Jeff
From: Michael
Priestley [mailto:]
Sent: Tuesday, October 02, 2007
2:15 PM
To: Ogden, Jeff
Cc:
Subject: Re: [dita] MUST, SHOULD,
and MAY, some key words from RFC 2119
Looks good, Jeff - with the caveat though that even
though the core is MUST and the specializations are RECOMMENDED or OPTIONAL, a
specialization may introduce behavior that overrides the core.
In
other words, all behavior, core and specialized, is overrideable.
Michael
Priestley
Lead IBM DITA Architect
http://dita.xml.org/blog/25
"Ogden, Jeff"
<>
10/02/2007 02:08 PM
To
<>
cc
Subject
[dita] MUST, SHOULD, and MAY, some key words
from RFC 2119
Included below are some words taken from RFC 2119 on “Key words
for use in RFCs to Indicate Requirement Levels". I think we are going to
need to use this or a similar approach in the DITA standard.
1.
MUST This word, or the terms "REQUIRED" or "SHALL",
mean that the
definition is an absolute requirement of the specification.
2.
MUST NOT This phrase, or the phrase "SHALL NOT", mean that the
definition is an absolute prohibition of the specification.
3.
SHOULD This word, or the adjective "RECOMMENDED", mean that
there
may exist valid reasons in particular circumstances to ignore a
particular item, but the full implications must be understood and
carefully weighed before choosing a different course.
4.
SHOULD NOT This phrase, or the phrase "NOT RECOMMENDED" mean
that
there may exist valid reasons in particular circumstances when the
particular behavior is acceptable or even useful, but the full
implications should be understood and the case carefully weighed
before implementing any behavior described with this label.
5. MAY
This word, or the adjective "OPTIONAL", mean that an item is
truly optional. One vendor may choose to include the item because a
particular marketplace requires it or because the vendor feels that
it enhances the product while another vendor may omit the same item.
An implementation which does not include a particular option MUST be
prepared to interoperate with another implementation which does
include the option, though perhaps with reduced functionality. In the
same vein an implementation which does include a particular option
MUST be prepared to interoperate with another implementation which
does not include the option (except, of course, for the feature the
option provides.)
To see
the full RFC (its short), see: http://www.ietf.org/rfc/rfc2119.txt?number=2119
Note
that as we split the DITA Specification into multiple specifications, that an
entire specification may be REQUIRED, RECOMMENDED, or OPTIONAL, but within the
individual specifications there will be items that are REQUIRED, RECOMMENDED or
which are OPTIONAL.
So, if
I take the summary from Michael’s recent note:
- everyone
needs to support the core;
- specialized
support (beyond core defaults) for the specialized parts of the spec are
optional but encouraged, and should represent an established user community;
- specialized
support (beyond core defaults or standard specialization defaults) for
non-standardized user specializations are up to the user or their partners to
provide
I can
rewrite it using the RFC terms as follows:
- everyone
MUST support the core;
- specialized
support (beyond core defaults) for the specialized parts of the spec are
RECOMMENDED, and MUST represent an established user community;
- specialized
support (beyond core defaults or standard specialization defaults) for
non-standardized user specializations is OPTIONAL and up to the user or their
partners to provide.
Michael,
how did I do?
-Jeff
