SPC Inquiry for Quad-Aligned Zero -- deprecated since SPC-4 maybe

plavarre at lexar.com plavarre at lexar.com
Fri Jan 4 17:25:48 PST 2008


* From the T10 Reflector (t10 at t10.org), posted by:
* <plavarre at lexar.com>
*
> Should does not necessarily mean that there
> is also a "should not", unless in fact, it is really there
Yep.
> I'm content with the text as is
Eh?
The Spc4r11.pdf text as is includes such fragments as: """If EVPD is set
to zero, the allocation length should be at least five, so that the
ADDITIONAL LENGTH field in the parameter data (see 6.4.2) is
returned."""
I think that fragment includes a false should not.
I think the phrase "should be at least five" means "should not be zero,
nor one, nor two, nor three, nor four" which I think is a claim false by
overstatement, because I think zero is fine as the allocation length,
even when EVPD is set to zero.
Where have I gone wrong in my reading with this logic?
Doesn't unsigned byte pair "should be at least five" always mean "should
not be zero, nor one, nor two, nor three, nor four"?
I think we should stop misleading by claiming should not be zero.
> > > the definition of the 'should' keyword
I think the applicable Spcr411.pdf definitions for 'may', 'should',
'shall' are:
"""3.3.5 may: A keyword that indicates flexibility of choice with no
implied preference (equivalent to "may or may
not")."""
"""3.3.6 may not: A keyword that indicates flexibility of choice with no
implied preference (equivalent to "may or may
not")."""
"""3.3.12 should: A keyword indicating flexibility of choice with a
strongly preferred alternative; equivalent to the phrase "it is strongly
recommended"."""
"""3.3.11 shall: A keyword indicating a mandatory requirement. Designers
are required to implement all such
mandatory requirements to ensure interoperability with other products
that conform to this standard."""
I don't yet understand which details of these definitions should be
directing my logic elsewhere.
I think unsigned may or shall or should be "at least" means should not
be less, which is wrong in this instance.
I'm most curious to understand where I've gone wrong. I don't see how
I've gone wrong. This looks like plain obvious logic to me -- a clear
matter of technical speaking. Somehow no?
Curiously yours, happy Friday,
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