[tei-council] Report back on feature request to remove redundant *-iso attributes

David Sewell dsewell at virginia.edu
Mon Oct 27 19:51:55 EDT 2008

Re: Tracker item 2055864


I've had a fairly lengthy email exchange with Syd Bauman over the past 
few days (if anybody wishes, I can bundle the messages as a text 
document and post them to the list) on this feature request, and our 
recommendations in brief are:

1. For the time being, take no action on the request. The main reason is 
that Lou's initial request makes the assumption that, given the 
flexibility of ISO 8601 syntax, @when-iso is capable of being fully 
synonymous with any of the other att.datable.iso attributes (largely 
because the syntax permits (a) the expression of a duration, and (b) the 
expression of from-to intervals using a solidus (/) separator. But in 
fact there is no way in ISO 8601 syntax to express the semantics of 
"notBefore" and "notAfter", so @notBefore-iso and @notAfter-iso could 
not be eliminated without loss of expressive ability, which defeats the 
goal of conflating the *-iso atttributes into att.datable.

2. The main thing you can do with full ISO 8601 date/time syntax that 
you can't do with the W3C Schema datatype subset of ISO 8601, beside 
expressing intervals using a "/" separator, is to represent dates and 
times with reduced accuracy. For example, to express "from 2 to 3 p.m.", 
W3C syntax requires
   <time from="14:00:00" to="15:00:00"/>
whereas with ISO 8601 you can say
   <time from-iso="T14" to="T15"/>
which some people prefer as it makes no implicit claim to precision.

Syd thinks that if the main (or only) thing we get out of adding ISO 
8601 syntax is a way of expessing imprecise times, we should investigate 
whether we can eliminate the *-iso attribute series in favor of some 
other way, using new attributes, to express the same thing.

In the meantime, he and I are going to see whether we think we can come 
up with a regular expression pattern that more accurately constrains the 
allowable values for the *-iso series, as the current pattern facet is 
too permissive.

I'd also add that, having gone to the trouble of adding the whole 
att.datable.iso class for P5, it would be a bit odd to withdraw it 
mid-stream, so I don't see this as anything that could happen before P6 
in any case. (For reference, the first proposal for adding an ISO class 
was in Syd's Council email from 2007-01:




David Sewell, Editorial and Technical Manager
ROTUNDA, The University of Virginia Press
PO Box 801079, Charlottesville, VA 22904-4318 USA
Courier: 310 Old Ivy Way, Suite 302, Charlottesville VA 22903
Email: dsewell at virginia.edu   Tel: +1 434 924 9973
Web: http://rotunda.upress.virginia.edu/

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