Dear Jonathan et al:
  
 a data point ....
  
 As an engineer working an operational data production system with 
schedules and deadlines, and the requirement to use NetCDF file format we 
are leveraging CF conventions wherever consensus has been reached.
  
 The benefit of using these conventions (regardless of their provisional 
status) outweighs any risk of their retraction.
  
 I am curious what other folks working operational data production systems 
are doing in this regard.
  
 very respectfully,
  
 randy
  
  
  

----------------------------------------
 From: "Jonathan Gregory" <j.m.greg...@reading.ac.uk>
Sent: Tuesday, March 18, 2014 7:09 AM
To: cf-metadata@cgd.ucar.edu
Subject: Re: [CF-metadata] Editing/publishing workflow   
Dear Richard

That's right. No change since 1.0 has so far passed beyond being 
"provisional"
since we didn't definitely agree how to do that. I am not strongly in 
favour of
provisional status myself, but others have argued strongly for it 
previously.
I think there is a good argument that we should try hard to avoid making a
mistake which we have to reverse, because data lasts forever, and if data 
were
written with a flawed standard, it would forever be a nuisance. Of course 
in
principle this can be detected and perhaps worked round using the version 
from
the Conventions attribute, but in practice I suspect this attribute is not
normally written scrupulously correctly, nor inspected by analysis 
software.
So we should be careful, and that means a "cooling-off" period during 
which
data is at risk of being invalidated if it uses a provisional convention is 
a
reasonable safeguard, but it should not be a long period - months, not 
years,
I would say.

Best wishes

Jonathan

----- Forwarded message from "Hattersley, Richard" 
<richard.hatters...@metoffice.gov.uk> -----

> Date: Tue, 18 Mar 2014 09:05:36 +0000
> From: "Hattersley, Richard" <richard.hatters...@metoffice.gov.uk>
> To: "Gregory, Jonathan" <j.m.greg...@reading.ac.uk>,
> "cf-metadata@cgd.ucar.edu" <cf-metadata@cgd.ucar.edu>
> Subject: RE: [CF-metadata] Editing/publishing workflow
>
> > I'd like to propose changing the rules. That's something the 
conventions committee can agree, I believe. I would suggest the simplest 
possibility, if we wish to retain provisional status, is to specify a time. 
We could say that, after one year from acceptance or when the next version 
of the conventions document is published, whichever is later, a change 
becomes permanent. What do you think?
>
> The more I consider the concept of "provisional status" the more it 
concerns me. What does it actually mean for a netCDF file to use a 
particular "Conventions" attribute value? How can one tell what is still in 
provisional status? What version should data writers be using? I've checked 
back through 1.3, 1.4, 1.5, and 1.6 and they all still contain sections 
marked as provisional. Using the analogy to software versions that has been 
raised elsewhere, the CF convention versions are essentially pre-release 
versions, e.g. 1.6-beta, and are not suitable for production use.
>
> I would argue that the simplest possibility is to drop the "provisional 
status" concept. Identifying and resolving problems should happen during 
the discussion of the modification and its subsequent application to the 
conventions document.
>
> If a further flaw, ambiguity, etc. is subsequently discovered prior to 
the publication of the next version of the conventions then it can easily 
be resolved at that time.
>
> If a problem is discovered after the publication of the next version then 
a correction must be applied and published in a *new* version. That version 
could be a "bug fix" version (e.g. 1.6.1) or it could just wait for the 
next normal release, e.g. 1.7. It would help to agree that process in 
advance but I have no strong opinion either way.
>
>
> Richard Hattersley
> Expert Software Developer
> Met Office FitzRoy Road Exeter Devon EX1 3PB United Kingdom
> Tel: +44 (0)1392 885702
> Email: richard.hatters...@metoffice.gov.uk Web: www.metoffice.gov.uk
>
> -----Original Message-----
> From: CF-metadata [mailto:cf-metadata-boun...@cgd.ucar.edu] On Behalf Of 
Jonathan Gregory
> Sent: 13 March 2014 17:24
> To: cf-metadata@cgd.ucar.edu
> Subject: Re: [CF-metadata] Editing/publishing workflow
>
> Dear Jeff
>
> > Present CF Conventions policies require that all changes be
> > provisional, and marked as such in the document, until determined to
> > be permanent at a later time (this determination has never been made).
> > That's the meaning of all the pink and yellow highlighting in the
> > document at cf-pcmdi.llnl.gov.
>
> Yes, this is a issue. As Richard said, it doesn't matter how it is 
marked. The problem is that all changes, however old, are still marked as 
provisional, as you said. This is (a) a bit silly and (b) a nuisance as 
regards legibility of the doc. The aim of provisional status was to allow 
time for people to try out the change, in case a logical flaw was 
discovered which hadn't been fore- seen at the time of the proposal. This 
was because of the concern that many or most proposals concern data which 
has not yet been written, so the metadata being proposed can't have been 
thoroughly tested. It was supposed that some tests, using specified 
software, would be used to demonstrate the new feature was "working", but 
no-one had time to work out the details for this.
>
> I'd like to propose changing the rules. That's something the conventions 
committee can agree, I believe. I would suggest the simplest possibility, 
if we wish to retain provisional status, is to specify a time. We could say 
that, after one year from acceptance or when the next version of the 
conventions document is published, whichever is later, a change becomes 
permanent. What do you think?
>
> Cheers
>
> Jonathan
> _______________________________________________
> CF-metadata mailing list
> CF-metadata@cgd.ucar.edu
> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata

----- End forwarded message -----
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