From: Michael
Priestley [mailto:mpriestl@ca.ibm.com]
Sent: Tuesday, October 02, 2007
2:41 PM
To: Ogden, Jeff
Cc: dita@lists.oasis-open.org
Subject: RE: [dita] MUST, SHOULD,
and MAY, some key words from RFC 2119
Yes, I think specific examples are good. Here are some
examples off the top of my head for overriding existing core behaviors:
-
conref: override current behavior to limit reuse to a particular set of targets
(eg only allow reuse from topics in a "/reuse" subdirectory)
-
map-based linking: create breadcrumb links (to all ancestors) instead of just
parent links
-
link resolution: pull the shortdesc for APIRef topics from their syntax as well
as their shortdesc
Some
of the overrides could be driven by specializations, some could just be driven
by business process requirements.
Michael
Priestley
Lead IBM DITA Architect
mpriestl@ca.ibm.com
http://dita.xml.org/blog/25
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"Ogden, Jeff"
<jogden@ptc.com>
10/02/2007 02:30 PM
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To
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Michael Priestley/Toronto/IBM@IBMCA
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cc
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<dita@lists.oasis-open.org>
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Subject
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RE: [dita] MUST, SHOULD, and MAY, some key
words from RFC 2119
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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:mpriestl@ca.ibm.com]
Sent: Tuesday, October 02, 2007 2:15 PM
To: Ogden, Jeff
Cc: dita@lists.oasis-open.org
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
mpriestl@ca.ibm.com
http://dita.xml.org/blog/25
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"Ogden, Jeff"
<jogden@ptc.com>
10/02/2007 02:08 PM
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To
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<dita@lists.oasis-open.org>
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cc
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Subject
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[dita] MUST, SHOULD, and MAY, some key words
from RFC 2119
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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